essay on different stages of human life

How it works

Transform your enterprise with the scalable mindsets, skills, & behavior change that drive performance.

Explore how BetterUp connects to your core business systems.

We pair AI with the latest in human-centered coaching to drive powerful, lasting learning and behavior change.

Build leaders that accelerate team performance and engagement.

Unlock performance potential at scale with AI-powered curated growth journeys.

Build resilience, well-being and agility to drive performance across your entire enterprise.

Transform your business, starting with your sales leaders.

Unlock business impact from the top with executive coaching.

Foster a culture of inclusion and belonging.

Accelerate the performance and potential of your agencies and employees.

See how innovative organizations use BetterUp to build a thriving workforce.

Discover how BetterUp measurably impacts key business outcomes for organizations like yours.

A demo is the first step to transforming your business. Meet with us to develop a plan for attaining your goals.

• What is coaching?

Learn how 1:1 coaching works, who its for, and if it's right for you.

Accelerate your personal and professional growth with the expert guidance of a BetterUp Coach.

Types of Coaching

Navigate career transitions, accelerate your professional growth, and achieve your career goals with expert coaching.

Enhance your communication skills for better personal and professional relationships, with tailored coaching that focuses on your needs.

Find balance, resilience, and well-being in all areas of your life with holistic coaching designed to empower you.

Discover your perfect match : Take our 5-minute assessment and let us pair you with one of our top Coaches tailored just for you.

Research, expert insights, and resources to develop courageous leaders within your organization.

Best practices, research, and tools to fuel individual and business growth.

View on-demand BetterUp events and learn about upcoming live discussions.

The latest insights and ideas for building a high-performing workplace.

• BetterUp Briefing

The online magazine that helps you understand tomorrow's workforce trends, today.

Innovative research featured in peer-reviewed journals, press, and more.

Founded in 2022 to deepen the understanding of the intersection of well-being, purpose, and performance

We're on a mission to help everyone live with clarity, purpose, and passion.

Join us and create impactful change.

Read the buzz about BetterUp.

Meet the leadership that's passionate about empowering your workforce.

For Business

For Individuals

The 8 life stages and what we can learn from each one

Jump to section

What are the stages of life?

The 8 stages of life, other theories about the stages of life, how to navigate and thrive through the stages of life.

If someone asked you what stage of your life you are in, what would you say?

Many of us think of the stages of life as simply childhood and adulthood. But can our lives really be summed up into two basic categories?

Throughout our lifetimes, we experience drastic changes and big milestones. From the day we are born, we are constantly learning, growing, and developing.

As complex beings, it is difficult to summarize human development into clear-cut stages. But many practitioners in developmental psychology have created theories to help understand our intellectual and cognitive development better.

These theories give us a better idea of how we move through different life goals at different times.

Let’s explore the various stages of life and why understanding them can help your personal development .

The stages of life are the different phases that all individuals pass through in a regular lifetime. During each stage, most people will share common interests, actions, and behaviors .

When we talk about the concept of life stages, three distinct phases come to mind: childhood, adulthood, and old age. 

However, there is a greater degree of nuance to the life cycle of a human. We are all unique individuals that feel, think, and experience different things as we grow in years of age.

A dramatic lifestyle change often characterizes the transition to a different stage of life. People often say that someone is entering a new stage of life when they move out of their home, graduate, retire , or have children .

But how many stages of life are there? Well, that depends on who you ask.

Some developmentalists break up the human life span into nine stages . Others think twelve is a more suitable number . 

In some of these theories, the first stage is prenatal development. So in the eyes of some psychologists, the life cycle begins before birth. 

While there are many theories, the important thing to remember is that we are all individual humans with unique experiences. The stages of life framework is simply meant to be a lens through which to see our lives.

We’ll dive into more frameworks for the life stages soon, but let’s first discuss Erik Erikson’s popularized theory of psychosocial development.

Erik Erikson is a renowned American-German psychologist from the twentieth century. He specialized in the study of the ego and used psychoanalytical tools to both investigate and present his theories.

Erikson is famously responsible for developing the concepts of identity crisis and the stages of psychosocial development.

His theory of psychosocial development emphasizes social interactions. He argues that a person’s social contexts and experiences determine their personality.

Conflict is also central to the theory. In each stage of life, Erikson proposes a conflict. Each conflict is a turning point where a person faces a struggle to achieve a psychological quality. These conflicts then bring about the individual’s transition into the next stage.

So according to Erik Erikson’s theory, what are the stages of life? His hypothesis covers eight particular life stages as follows: 

• Toddlerhood
• Preschool years
• Early school years
• Adolescence
• Young adulthood
• Middle adulthood
• Late adulthood

When you are young, you might have some grandiose idea of where you see yourself in ten years. Plenty of kids dream of being superheroes or the president. But with time, these hopes and dreams will likely transform into a more grounded and specific vision .

As you grow into yourself, you cultivate a set of values , interests, and aspirations. Naturally, the personal goals of an eight-year-old will be very different from those of a forty-year-old.

Different life experiences help you grow and learn, and your outlook on the world changes. As your age increases, so does your level of maturity.

With more maturity comes a level of respect, compassion , and self-awareness . The relationship you have with yourself changes.

Infancy begins when an individual is born and continues until they are eighteen months old. This time is largely characterized by the infant’s relationship with their caregiver(s) and the conflict of trust vs. mistrust.

If they are well taken care of, the infant comes to trust their parent or guardian. If they are neglected, they will likely project this mistrust onto relationships during the other stages of their life.

Although individuals of all ages struggle with trust issues , it is a characteristic feature of this first stage of life.

The virtue of the infancy stage is hope. If an individual is adequately cared for as an infant and finds themselves in a challenging situation later in life, they are more inclined to believe that someone will come to their aid.

2. Toddlerhood

This early childhood stage spans from eighteen months to three years old. At this age, toddlers are beginning to learn independently. If a toddler’s sense of independence and self-confidence are encouraged, it nurtures their autonomy.

But if these young children are scolded or mocked for their curiosity, they may develop feelings of shame, self-doubt, and guilt. These insecurities could inhibit their personal growth because confidence is vital to evolving as a human being. Hence, the primary conflict is autonomy vs. shame and doubt.

The virtue of the toddler stage is will. A sense of will is a product of the child’s growing confidence in their physical and cognitive capacity.

3. Preschool years

The preschool years range from ages three to five. At this age, the primary conflict is between initiative and guilt. As with toddlerhood, this is a symptom of their attempts to learn independently and become more fully formed as human beings.

If a child’s caregiver encourages them to do things on their own, they grow to become individuals who take initiative and have a purpose in life . If their caregivers criticize and demotivate them, they develop guilt.

Unlike earlier stages, interactions with other children of roughly the same age facilitate most of the development here.

4. Early school years

During the early school years, children are between the ages of five and twelve. They experience a tension between industry and inferiority.

At this stage in life, a child becomes increasingly self-aware. This self-actualization involves social and emotional development.

There is also a focus on cognitive development — you learn to read and write in this stage.

Accomplishment and praise will make a child at this stage industrious. But a lack of recognition results in feelings of failure and inferiority . If a child feels validated and supported in their endeavors, they will develop the virtue of competence.

5. Adolescence

This stage of life is famously turbulent. Between the ages of twelve and eighteen, most individuals will experience a crisis of identity. This period is forward-looking as teenagers consider their future and invest in social connections .

More than anything, the typical teenager wants to be accepted by their peers.

A teenager will explore the different types of roles that they can occupy as an adult. It is a period of all-consuming self-discovery, and this journey can be very confusing.

The virtue of adolescence is fidelity. A healthy support network will help a teenager to develop the ability to form relationships despite potential differences .

6. Young adulthood

Young adulthood happens between the ages of eighteen and forty. Typically, people in this stage are building the social, professional, and financial foundations they’ll need for the rest of their lives. 

The primary conflict of early adulthood is intimacy vs. isolation. This tension is based on the presence or absence of intimate personal relationships . The type of development is primarily social.

If a young adult avoids intimacy because they are afraid of failure, disappointment , or commitment, they are likely to feel isolated and alone . Young adults may experience things like a quarter-life crisis . Yet they may also start to learn from their failures . 

However, if they establish a solid social network , they will feel connected to — and hopefully understood by — the world around them. The virtue of this stage is an increased capacity for love.

7. Middle adulthood

According to Erikson, middle adulthood starts at forty and ends at sixty-five. The primary conflict during this midlife stage is the tug-of-war between generativity and stagnation . Generativity is an adult’s choice to pass on what they have learned to younger generations.

If an adult in this stage is unhappy or resentful about their life, they may choose to stew in their discontent and avoid contributing to society. If they decide to be a positive and productive member of their community, they will develop the virtue of care.

8. Late adulthood

The eighth and final stage of life is late adulthood. This stage refers to any individual who is older than sixty-five years old.

Late adulthood is a time of deep reflection and introspection . If you are proud of the life that you have led, then you should feel a sense of peace. If, however, you are haunted by regrets and failures, you will likely experience despair and resentment.

According to Erikson, either ego-integrity or ego-despair characterizes the end of life for older adults. The virtue of this stage is wisdom.

Erik Erickson’s theory isn’t the only one out there — for years, philosophers, psychologists, and academics have debated the number of life stages and when they occur. To get a better perspective on all the stages of life and how this framework can help you, let’s take a look at some of the other theories. 

Jean Piaget’s theory of cognitive development

While Erikson proposes eight stages of life, Jean Piaget proposes only four. His theory looks at the nature of intelligence . He believes that the way children acquire knowledge determines the progression of mental development.

These stages are:

• sensorimotor (birth to two years old)
• preoperational (ages two to seven)
• concrete operational (ages seven to eleven)
• formal operational (twelve years and older)

Piaget emphasizes the importance of curiosity in cognitive development .

Daniel Levinson’s Seasons of Life Theory

Unlike Piaget’s theory, which ends in the adolescent stage of life, Levinson looks at an individual’s entire life . He emphasizes the development that happens as an adult.

The Seasons of Life Theory consists of sequence-like stages. These stages occur during two types of periods. The Stable Period is when we make crucial life choices. The Transitional Period is when one stage ends and another begins.

The major shortcoming of this theory is that the research relates solely to men’s experiences. Levinson chose to interview only biological men.

Klaus Riegel’s Dimension of Development

Riegel’s theory doesn’t map a uniform process of development. Instead, his theory highlights the unpredictable nature of life.

Riegel proposes that personal development happens because of external and internal changes you experience in your adult life.

He outlines four interrelated internal and external dimensions of development:

• The internal psychological level includes emotional intelligence and mental capacity. 
• The internal physical dimension describes physical and sexual maturity.
• The external cultural-sociological dimension refers to the expectations and opportunities of society.
• The external environmental dimension includes the political, physical, and economic context in which an individual lives.

Although we can describe the human life cycle in clear-cut stages, we continually and gradually change from day to day. 

To navigate and thrive through these stages of life, you need to prepare yourself to take the lessons of one stage into the next. That way, you can keep growing into a happier, better version of yourself as you progress through the stages of life. 

Here are a few ways you can do that: 

• Process your childhood trauma with the help of mental healthcare professional 
• Prioritize your personal growth by doing inner child and shadow work 
• Understand your patterns and what’s really important to you by going on a self-discovery journey  
• Commit to making the life changes you know you need to by enlisting the support of a coach or family and friends  

These practices will help your maturity increase as your age does. That’s good for both you and your loved ones — with more maturity comes more respect for yourself and others, more compassion , and more self-awareness . 

Progressing through the stages of life can be challenging, but it’s exciting because it gives us the opportunity to become our authentic selves . If you can learn how to navigate through the waves of change, you’ll be grateful for all the chances life gives you to grow.

Understand the stages of life for personal growth

Life is a journey of self-discovery . Throughout, you’ll find learning opportunities for becoming a better friend, partner, and family member.

The growth and change we experience throughout our lives go beyond the physical realm. We have self-conscious, self-reflective, and social capabilities that we can develop.

By understanding the stages of life and what each phase entails, you can develop your self-awareness . And with self-awareness, you can live your life with purpose and intention.

While there may be bumps along the road, the challenges we are faced with are opportunities to grow. Personal growth is not necessarily easy, but it is rewarding.

If you’re looking to invest in your personal growth and are seeking professional and structured guidance, contact BetterUp today .

Transform your life

Make meaningful changes and become the best version of yourself. BetterUp's professional Coaches are here to support your personal growth journey.

Elizabeth Perry, ACC

Elizabeth Perry is a Coach Community Manager at BetterUp. She uses strategic engagement strategies to cultivate a learning community across a global network of Coaches through in-person and virtual experiences, technology-enabled platforms, and strategic coaching industry partnerships. With over 3 years of coaching experience and a certification in transformative leadership and life coaching from Sofia University, Elizabeth leverages transpersonal psychology expertise to help coaches and clients gain awareness of their behavioral and thought patterns, discover their purpose and passions, and elevate their potential. She is a lifelong student of psychology, personal growth, and human potential as well as an ICF-certified ACC transpersonal life and leadership Coach.

5 stages of grief and ways to start healing

Identifying different life crisis stages and how to cope, midlife crisis doesn't have to be: learn to navigate it with grace, social learning theory: bandura’s hypothesis (+ examples), understanding grief for what it is and how we mourn, the 6 stages of behavior change: a how-to guide, what is rem sleep and why is it important, empty nest syndrome: how to cope when kids fly the coop, where's the romance why (and how) to talk money when you're set on marriage, similar articles, are you going through an identity crisis 5 ways to cope, what’s generativity vs. stagnation it's a step closer to your goals, young men lag in developing this key skill that’s linked to achievement and success, 4 ways to overcome your quarter-life crisis (and redefining success), what we can learn from “pandemic thrivers”, stay connected with betterup, get our newsletter, event invites, plus product insights and research..

3100 E 5th Street, Suite 350 Austin, TX 78702

• Platform Overview
• Integrations
• Powered by AI
• BetterUp Lead
• BetterUp Manage™
• BetterUp Care™
• Sales Performance
• Diversity & Inclusion
• Case Studies
• Why BetterUp?
• About Coaching
• Find your Coach
• Career Coaching
• Communication Coaching
• Life Coaching
• News and Press
• Leadership Team
• Become a BetterUp Coach
• BetterUp Labs
• Center for Purpose & Performance
• Leadership Training
• Business Coaching
• Contact Support
• Contact Sales
• Privacy Policy
• Acceptable Use Policy
• Trust & Security
• Cookie Preferences

Want to create or adapt books like this? Learn more about how Pressbooks supports open publishing practices.

Ch 3: Lifespan Development

Welcome to the story of your life. In this chapter, we will explore the fascinating tale of how you have grown and developed into the person you are today. We will also look at some ideas about who you will grow into tomorrow. Yours is a story of lifespan development (Figure 1), from the start of life to the end.

The process of human growth and development is more obvious in infancy and childhood, yet your development is happening this moment and will continue, minute by minute, for the rest of your life. Who you are today and who you will be in the future depends on a blend of genetics, environment, culture, relationships, and more, as you continue through each phase of life. You have experienced firsthand much of what is discussed in this chapter. Now consider what psychological science has to say about your physical, cognitive, and psychosocial development, from the womb to the tomb.

Theories of Development

There are many theories regarding how babies and children grow and develop into happy, healthy adults. Sigmund Freud suggested that we pass through a series of psychosexual stages in which our energy is focused on certain erogenous zones on the body. Eric Erikson modified Freud’s ideas and suggested a theory of psychosocial development. Erikson said that our social interactions and successful completion of social tasks shape our sense of self. Jean Piaget proposed a theory of cognitive development that explains how children think and reason as they move through various stages. Finally, Lawrence Kohlberg turned his attention to moral development. He said that we pass through three levels of moral thinking that build on our cognitive development. You’ll learn about each of these theories in this section.

Learning Objectives

• Describe the three major issues in development: continuity and discontinuity, one common course of development or many unique courses of development, and nature versus nurture

What Is Lifespan Development?

My heart leaps up when I behold A rainbow in the sky: So was it when my life began; So is it now I am a man; So be it when I shall grow old, Or let me die! The Child is father of the Man; And I could wish my days to be Bound each to each by natural piety. (Wordsworth, 1802)

In this poem, William Wordsworth writes, “the child is father of the man.” What does this seemingly incongruous statement mean, and what does it have to do with lifespan development? Wordsworth might be suggesting that the person he is as an adult depends largely on the experiences he had in childhood. Consider the following questions: To what extent is the adult you are today influenced by the child you once were? To what extent is a child fundamentally different from the adult he grows up to be?

These are the types of questions developmental psychologists try to answer, by studying how humans change and grow from conception through childhood, adolescence, adulthood, and death. They view development as a lifelong process that can be studied scientifically across three developmental domains—physical, cognitive, and psychosocial development. Physical development involves growth and changes in the body and brain, the senses, motor skills, and health and wellness. Cognitive development involves learning, attention, memory, language, thinking, reasoning, and creativity. Psychosocial development involves emotions, personality, and social relationships. We refer to these domains throughout the module.

Connect the Concepts: Research Methods in Developmental Psychology

You’ve learned about a variety of research methods used by psychologists. Developmental psychologists use many of these approaches in order to better understand how individuals change mentally and physically over time. These methods include naturalistic observations, case studies, surveys, and experiments, among others.

Naturalistic observations involve observing behavior in its natural context. A developmental psychologist might observe how children behave on a playground, at a daycare center, or in the child’s own home. While this research approach provides a glimpse into how children behave in their natural settings, researchers have very little control over the types and/or frequencies of displayed behavior.

In a case study, developmental psychologists collect a great deal of information from one individual in order to better understand physical and psychological changes over the lifespan. This particular approach is an excellent way to better understand individuals, who are exceptional in some way, but it is especially prone to researcher bias in interpretation, and it is difficult to generalize conclusions to the larger population.

In one classic example of this research method being applied to a study of lifespan development Sigmund Freud analyzed the development of a child known as “Little Hans” (Freud, 1909/1949). Freud’s findings helped inform his theories of psychosexual development in children, which you will learn about later in this module. Little Genie, the subject of a case study discussed in the module on thinking and intelligence, provides another example of how psychologists examine developmental milestones through detailed research on a single individual. In Genie’s case, her neglectful and abusive upbringing led to her being unable to speak until, at age 13, she was removed from that harmful environment. As she learned to use language, psychologists were able to compare how her language acquisition abilities differed when occurring in her late-stage development compared to the typical acquisition of those skills during the ages of infancy through early childhood (Fromkin, Krashen, Curtiss, Rigler, & Rigler, 1974; Curtiss, 1981).

The survey method asks individuals to self-report important information about their thoughts, experiences, and beliefs. This particular method can provide large amounts of information in relatively short amounts of time; however, validity of data collected in this way relies on honest self-reporting, and the data is relatively shallow when compared to the depth of information collected in a case study.

Experiments involve significant control over extraneous variables and manipulation of the independent variable. As such, experimental research allows developmental psychologists to make causal statements about certain variables that are important for the developmental process. Because experimental research must occur in a controlled environment, researchers must be cautious about whether behaviors observed in the laboratory translate to an individual’s natural environment.

Later in this chapter, you will learn about several experiments in which toddlers and young children observe scenes or actions so that researchers can determine at what age specific cognitive abilities develop. For example, children may observe a quantity of liquid poured from a short, fat glass into a tall, skinny glass. As the experimenters question the children about what occurred, the subjects’ answers help psychologists understand at what age a child begins to comprehend that the volume of liquid remained the same although the shapes of the containers differs.

Across these three domains—physical, cognitive, and psychosocial—the normative approach to development is also discussed. This approach asks, “What is normal development?” In the early decades of the 20th century, normative psychologists studied large numbers of children at various ages to determine norms (i.e., average ages) of when most children reach specific developmental milestones in each of the three domains (Gesell, 1933, 1939, 1940; Gesell & Ilg, 1946; Hall, 1904). Although children develop at slightly different rates, we can use these age-related averages as general guidelines to compare children with same-age peers to determine the approximate ages they should reach specific normative events called developmental milestones  (e.g., crawling, walking, writing, dressing, naming colors, speaking in sentences, and starting puberty).

Not all normative events are universal, meaning they are not experienced by all individuals across all cultures. Biological milestones, such as puberty, tend to be universal, but social milestones, such as the age when children begin formal schooling, are not necessarily universal; instead, they affect most individuals in a particular culture (Gesell & Ilg, 1946). For example, in developed countries children begin school around 5 or 6 years old, but in developing countries, like Nigeria, children often enter school at an advanced age, if at all (Huebler, 2005; United Nations Educational, Scientific, and Cultural Organization [UNESCO], 2013).

To better understand the normative approach, imagine two new mothers, Louisa and Kimberly, who are close friends and have children around the same age. Louisa’s daughter is 14 months old, and Kimberly’s son is 12 months old. According to the normative approach, the average age a child starts to walk is 12 months. However, at 14 months Louisa’s daughter still isn’t walking. She tells Kimberly she is worried that something might be wrong with her baby. Kimberly is surprised because her son started walking when he was only 10 months old. Should Louisa be worried? Should she be concerned if her daughter is not walking by 15 months or 18 months?

Link to Learning

Issues in developmental psychology, is development continuous or discontinuous.

Continuous development views development as a cumulative process, gradually improving on existing skills (Figure 2). With this type of development, there is gradual change. Consider, for example, a child’s physical growth: adding inches to her height year by year. In contrast, theorists who view development as discontinuous  believe that development takes place in unique stages: It occurs at specific times or ages. With this type of development, the change is more sudden, such as an infant’s ability to conceive object permanence.

Is There One Course of Development or Many?

Is development essentially the same, or universal, for all children (i.e., there is one course of development) or does development follow a different course for each child, depending on the child’s specific genetics and environment (i.e., there are many courses of development)? Do people across the world share more similarities or more differences in their development? How much do culture and genetics influence a child’s behavior?

Stage theories hold that the sequence of development is universal. For example, in cross-cultural studies of language development, children from around the world reach language milestones in a similar sequence (Gleitman & Newport, 1995). Infants in all cultures coo before they babble. They begin babbling at about the same age and utter their first word around 12 months old. Yet we live in diverse contexts that have a unique effect on each of us. For example, researchers once believed that motor development follows one course for all children regardless of culture. However, child care practices vary by culture, and different practices have been found to accelerate or inhibit achievement of developmental milestones such as sitting, crawling, and walking (Karasik, Adolph, Tamis-LeMonda, & Bornstein, 2010).

For instance, let’s look at the Aché society in Paraguay. They spend a significant amount of time foraging in forests. While foraging, Aché mothers carry their young children, rarely putting them down in order to protect them from getting hurt in the forest. Consequently, their children walk much later: They walk around 23–25 months old, in comparison to infants in Western cultures who begin to walk around 12 months old. However, as Aché children become older, they are allowed more freedom to move about, and by about age 9, their motor skills surpass those of U.S. children of the same age: Aché children are able to climb trees up to 25 feet tall and use machetes to chop their way through the forest (Kaplan & Dove, 1987). As you can see, our development is influenced by multiple contexts, so the timing of basic motor functions may vary across cultures. However, the functions themselves are present in all societies (Figure 3).

How Do Nature and Nurture Influence Development?

Are we who we are because of nature (biology and genetics), or are we who we are because of nurture (our environment and culture)? This longstanding question is known in psychology as the nature versus nurture debate. It seeks to understand how our personalities and traits are the product of our genetic makeup and biological factors, and how they are shaped by our environment, including our parents, peers, and culture. For instance, why do biological children sometimes act like their parents—is it because of genetics or because of early childhood environment and what the child has learned from the parents? What about children who are adopted—are they more like their biological families or more like their adoptive families? And how can siblings from the same family be so different?

We are all born with specific genetic traits inherited from our parents, such as eye color, height, and certain personality traits. Beyond our basic genotype, however, there is a deep interaction between our genes and our environment: Our unique experiences in our environment influence whether and how particular traits are expressed, and at the same time, our genes influence how we interact with our environment (Diamond, 2009; Lobo, 2008). This module will show that there is a reciprocal interaction between nature and nurture as they both shape who we become, but the debate continues as to the relative contributions of each.

Dig Deeper: The Achievement Gap: How Does Socioeconomic Status Affect Development?

The achievement gap refers to the persistent difference in grades, test scores, and graduation rates that exist among students of different ethnicities, races, and—in certain subjects—sexes (Winerman, 2011). Research suggests that these achievement gaps are strongly influenced by differences in socioeconomic factors that exist among the families of these children. While the researchers acknowledge that programs aimed at reducing such socioeconomic discrepancies would likely aid in equalizing the aptitude and performance of children from different backgrounds, they recognize that such large-scale interventions would be difficult to achieve. Therefore, it is recommended that programs aimed at fostering aptitude and achievement among disadvantaged children may be the best option for dealing with issues related to academic achievement gaps (Duncan & Magnuson, 2005).

Low-income children perform significantly more poorly than their middle- and high-income peers on a number of educational variables: They have significantly lower standardized test scores, graduation rates, and college entrance rates, and they have much higher school dropout rates. There have been attempts to correct the achievement gap through state and federal legislation, but what if the problems start before the children even enter school?

Psychologists Betty Hart and Todd Risley (2006) spent their careers looking at early language ability and progression of children in various income levels. In one longitudinal study, they found that although all the parents in the study engaged and interacted with their children, middle- and high-income parents interacted with their children differently than low-income parents. After analyzing 1,300 hours of parent-child interactions, the researchers found that middle- and high-income parents talk to their children significantly more, starting when the children are infants. By 3 years old, high-income children knew almost double the number of words known by their low-income counterparts, and they had heard an estimated total of 30 million more words than the low-income counterparts (Hart & Risley, 2003). And the gaps only become more pronounced. Before entering kindergarten, high-income children score 60% higher on achievement tests than their low-income peers (Lee & Burkam, 2002).

There are solutions to this problem. At the University of Chicago, experts are working with low-income families, visiting them at their homes, and encouraging them to speak more to their children on a daily and hourly basis. Other experts are designing preschools in which students from diverse economic backgrounds are placed in the same classroom. In this research, low-income children made significant gains in their language development, likely as a result of attending the specialized preschool (Schechter & Byeb, 2007). What other methods or interventions could be used to decrease the achievement gap? What types of activities could be implemented to help the children of your community or a neighboring community?

Think It Over

• How are you different today from the person you were at 6 years old? What about at 16 years old? How are you the same as the person you were at those ages?
• Your 3-year-old daughter is not yet potty trained. Based on what you know about the normative approach, should you be concerned? Why or why not?

Lifespan Theories

• Define Freud’s theory of psychosexual development
• Describe the major tasks of child and adult psychosocial development according to Erikson
• Discuss Piaget’s view of cognitive development and apply the stages to understanding childhood cognition
• Describe Kohlberg’s theory of moral development
• Compare and contrast the strengths and weaknesses of major developmental theories

Psychosexual Theory of Development

Sigmund Freud (1856–1939) believed that personality develops during early childhood. For Freud, childhood experiences shape our personalities and behavior as adults. Freud viewed development as discontinuous; he believed that each of us must pass through a serious of stages during childhood, and that if we lack proper nurturance and parenting during a stage, we may become stuck, or fixated, in that stage. Freud’s stages are called the stages of psychosexual development . According to Freud, children’s pleasure-seeking urges are focused on a different area of the body, called an erogenous zone, at each of the five stages of development: oral, anal, phallic, latency, and genital.

While most of Freud’s ideas have not found support in modern research, we cannot discount the contributions that Freud has made to the field of psychology. Psychologists today dispute Freud’s psychosexual stages as a legitimate explanation for how one’s personality develops, but what we can take away from Freud’s theory is that personality is shaped, in some part, by experiences we have in childhood. These stages are discussed in detail in the personality chapter in OpenStax .

Psychosocial Theory of Development

Erik Erikson (1902–1994) (Figure 4), another stage theorist, took Freud’s theory and modified it as psychosocial theory. Erikson’s psychosocial development  emphasizes the social nature of our development rather than its sexual nature. While Freud believed that personality is shaped only in childhood, Erikson proposed that personality development takes place all through the lifespan. Erikson suggested that how we interact with others is what affects our sense of self, or what he called the ego identity.

Erikson proposed that we are motivated by a need to achieve competence in certain areas of our lives. According to psychosocial theory, we experience eight stages of development over our lifespan, from infancy through late adulthood. At each stage there is a conflict, or task, that we need to resolve. Successful completion of each developmental task results in a sense of competence and a healthy personality. Failure to master these tasks leads to feelings of inadequacy.

According to Erikson (1963), trust is the basis of our development during infancy (birth to 12 months). Therefore, the primary task of this stage is trust versus mistrust. Infants are dependent upon their caregivers, so caregivers who are responsive and sensitive to their infant’s needs help their baby to develop a sense of trust; their baby will see the world as a safe, predictable place. Unresponsive caregivers who do not meet their baby’s needs can engender feelings of anxiety, fear, and mistrust; their baby may see the world as unpredictable.

As toddlers (ages 1–3 years) begin to explore their world, they learn that they can control their actions and act on the environment to get results. They begin to show clear preferences for certain elements of the environment, such as food, toys, and clothing. A toddler’s main task is to resolve the issue of autonomy versus shame and doubt, by working to establish independence. This is the “me do it” stage. For example, we might observe a budding sense of autonomy in a 2-year-old child who wants to choose her clothes and dress herself. Although her outfits might not be appropriate for the situation, her input in such basic decisions has an effect on her sense of independence. If denied the opportunity to act on her environment, she may begin to doubt her abilities, which could lead to low self-esteem and feelings of shame.

Once children reach the preschool stage (ages 3–6 years), they are capable of initiating activities and asserting control over their world through social interactions and play. According to Erikson, preschool children must resolve the task of initiative versus guilt. By learning to plan and achieve goals while interacting with others, preschool children can master this task. Those who do will develop self-confidence and feel a sense of purpose. Those who are unsuccessful at this stage—with their initiative misfiring or stifled—may develop feelings of guilt. How might over-controlling parents stifle a child’s initiative?

During the elementary school stage (ages 6–12), children face the task of industry versus inferiority. Children begin to compare themselves to their peers to see how they measure up. They either develop a sense of pride and accomplishment in their schoolwork, sports, social activities, and family life, or they feel inferior and inadequate when they don’t measure up. What are some things parents and teachers can do to help children develop a sense of competence and a belief in themselves and their abilities?

In adolescence (ages 12–18), children face the task of identity versus role confusion. According to Erikson, an adolescent’s main task is developing a sense of self. Adolescents struggle with questions such as “Who am I?” and “What do I want to do with my life?” Along the way, most adolescents try on many different selves to see which ones fit. Adolescents who are successful at this stage have a strong sense of identity and are able to remain true to their beliefs and values in the face of problems and other people’s perspectives. What happens to apathetic adolescents, who do not make a conscious search for identity, or those who are pressured to conform to their parents’ ideas for the future? These teens will have a weak sense of self and experience role confusion. They are unsure of their identity and confused about the future.

People in early adulthood (i.e., 20s through early 40s) are concerned with intimacy versus isolation. After we have developed a sense of self in adolescence, we are ready to share our life with others. Erikson said that we must have a strong sense of self before developing intimate relationships with others. Adults who do not develop a positive self-concept in adolescence may experience feelings of loneliness and emotional isolation.

When people reach their 40s, they enter the time known as middle adulthood, which extends to the mid-60s. The social task of middle adulthood is generativity versus stagnation. Generativity involves finding your life’s work and contributing to the development of others, through activities such as volunteering, mentoring, and raising children. Those who do not master this task may experience stagnation, having little connection with others and little interest in productivity and self-improvement.

From the mid-60s to the end of life, we are in the period of development known as late adulthood. Erikson’s task at this stage is called integrity versus despair. He said that people in late adulthood reflect on their lives and feel either a sense of satisfaction or a sense of failure. People who feel proud of their accomplishments feel a sense of integrity, and they can look back on their lives with few regrets. However, people who are not successful at this stage may feel as if their life has been wasted. They focus on what “would have,” “should have,” and “could have” been. They face the end of their lives with feelings of bitterness, depression, and despair. Table 1 summarizes the stages of Erikson’s theory.

Cognitive Theory of Development

Jean Piaget (1896–1980) is another stage theorist who studied childhood development (Figure 5). Instead of approaching development from a psychoanalytical or psychosocial perspective, Piaget focused on children’s cognitive growth. He believed that thinking is a central aspect of development and that children are naturally inquisitive. However, he said that children do not think and reason like adults (Piaget, 1930, 1932). His theory of cognitive development holds that our cognitive abilities develop through specific stages, which exemplifies the discontinuity approach to development. As we progress to a new stage, there is a distinct shift in how we think and reason.

Piaget said that children develop schemata, sometimes called schemas, to help them understand the world. Schemata  are concepts (mental models) that are used to help us categorize and interpret information. By the time children have reached adulthood, they have created schemata for almost everything. When children learn new information, they adjust their schemata through two processes: assimilation and accommodation. First, they assimilate new information or experiences in terms of their current schemata: assimilation is when they take in information that is comparable to what they already know. Accommodation  describes when they change their schemata based on new information. This process continues as children interact with their environment.

For example, 2-year-old Blake learned the schema for dogs because his family has a Labrador retriever. When Blake sees other dogs in his picture books, he says, “Look mommy, dog!” Thus, he has assimilated them into his schema for dogs. One day, Blake sees a sheep for the first time and says, “Look mommy, dog!” Having a basic schema that a dog is an animal with four legs and fur, Blake thinks all furry, four-legged creatures are dogs. When Blake’s mom tells him that the animal he sees is a sheep, not a dog, Blake must accommodate his schema for dogs to include more information based on his new experiences. Blake’s schema for dog was too broad, since not all furry, four-legged creatures are dogs. He now modifies his schema for dogs and forms a new one for sheep.

Like Freud and Erikson, Piaget thought development unfolds in a series of stages approximately associated with age ranges. He proposed a theory of cognitive development that unfolds in four stages: sensorimotor, preoperational, concrete operational, and formal operational.

The first stage is the sensorimotor stage, which lasts from birth to about 2 years old. During this stage, children learn about the world through their senses and motor behavior. Young children put objects in their mouths to see if the items are edible, and once they can grasp objects, they may shake or bang them to see if they make sounds. Between 5 and 8 months old, the child develops object permanence , which is the understanding that even if something is out of sight, it still exists (Bogartz, Shinskey, & Schilling, 2000). According to Piaget, young infants do not remember an object after it has been removed from sight. Piaget studied infants’ reactions when a toy was first shown to an infant and then hidden under a blanket. Infants who had already developed object permanence would reach for the hidden toy, indicating that they knew it still existed, whereas infants who had not developed object permanence would appear confused.

Please take a few minutes to view this brief video demonstrating different children’s ability to understand object permanence:

You can view the transcript for “Piaget – Stage 1 – Sensorimotor Stage : Object Permanence” here (opens in new window) .

In Piaget’s view, around the same time children develop object permanence, they also begin to exhibit stranger anxiety, which is a fear of unfamiliar people. Babies may demonstrate this by crying and turning away from a stranger, by clinging to a caregiver, or by attempting to reach their arms toward familiar faces such as parents. Stranger anxiety results when a child is unable to assimilate the stranger into an existing schema; therefore, she can’t predict what her experience with that stranger will be like, which results in a fear response.

Piaget’s second stage is the preoperational stage , which is from approximately 2 to 7 years old. In this stage, children can use symbols to represent words, images, and ideas, which is why children in this stage engage in pretend play. A child’s arms might become airplane wings as he zooms around the room, or a child with a stick might become a brave knight with a sword. Children also begin to use language in the preoperational stage, but they cannot understand adult logic or mentally manipulate information (the term operational refers to logical manipulation of information, so children at this stage are considered to be pre -operational). Children’s logic is based on their own personal knowledge of the world so far, rather than on conventional knowledge. For example, dad gave a slice of pizza to 10-year-old Keiko and another slice to her 3-year-old brother, Kenny. Kenny’s pizza slice was cut into five pieces, so Kenny told his sister that he got more pizza than she did. Children in this stage cannot perform mental operations because they have not developed an understanding of conservation , which is the idea that even if you change the appearance of something, it is still equal in size as long as nothing has been removed or added.

This video shows a 4.5-year-old boy in the preoperational stage as he responds to Piaget’s conservation tasks.

You can view the transcript for “A typical child on Piaget’s conservation tasks” here (opens in new window) .

During this stage, we also expect children to display egocentrism , which means that the child is not able to take the perspective of others. A child at this stage thinks that everyone sees, thinks, and feels just as they do. Let’s look at Kenny and Keiko again. Keiko’s birthday is coming up, so their mom takes Kenny to the toy store to choose a present for his sister. He selects an Iron Man action figure for her, thinking that if he likes the toy, his sister will too. An egocentric child is not able to infer the perspective of other people and instead attributes his own perspective. At some point during this stage and typically between 3 and 5 years old, children come to understand that people have thoughts, feelings, and beliefs that are different from their own. This is known as theory-of-mind  (TOM).

Piaget developed the Three-Mountain Task to determine the level of egocentrism displayed by children. Children view a 3-dimensional mountain scene from one viewpoint, and are asked what another person at a different viewpoint would see in the same scene. Watch the Three-Mountain Task in action in this short video from the University of Minnesota and the Science Museum of Minnesota.

You can view the transcript for “Piaget’s Mountains Task” here (opens in new window) .

Piaget’s third stage is the concrete operational stage , which occurs from about 7 to 11 years old. In this stage, children can think logically about real (concrete) events; they have a firm grasp on the use of numbers and start to employ memory strategies. They can perform mathematical operations and understand transformations, such as addition is the opposite of subtraction, and multiplication is the opposite of division. In this stage, children also master the concept of conservation: Even if something changes shape, its mass, volume, and number stay the same. For example, if you pour water from a tall, thin glass to a short, fat glass, you still have the same amount of water. Remember Keiko and Kenny and the pizza? How did Keiko know that Kenny was wrong when he said that he had more pizza?

Children in the concrete operational stage also understand the principle of reversibility , which means that objects can be changed and then returned back to their original form or condition. Take, for example, water that you poured into the short, fat glass: You can pour water from the fat glass back to the thin glass and still have the same amount (minus a couple of drops).

The fourth, and last, stage in Piaget’s theory is the formal operational stage , which is from about age 11 to adulthood. Whereas children in the concrete operational stage are able to think logically only about concrete events, children in the formal operational stage can also deal with abstract ideas and hypothetical situations. Children in this stage can use abstract thinking to problem solve, look at alternative solutions, and test these solutions. In adolescence, a renewed egocentrism occurs. For example, a 15-year-old with a very small pimple on her face might think it is huge and incredibly visible, under the mistaken impression that others must share her perceptions.

Beyond Formal Operational Thought

As with other major contributors of theories of development, several of Piaget’s ideas have come under criticism based on the results of further research. For example, several contemporary studies support a model of development that is more continuous than Piaget’s discrete stages (Courage & Howe, 2002; Siegler, 2005, 2006). Many others suggest that children reach cognitive milestones earlier than Piaget describes (Baillargeon, 2004; de Hevia & Spelke, 2010).

According to Piaget, the highest level of cognitive development is formal operational thought, which develops between 11 and 20 years old. However, many developmental psychologists disagree with Piaget, suggesting a fifth stage of cognitive development, known as the postformal stage (Basseches, 1984; Commons & Bresette, 2006; Sinnott, 1998). In postformal thinking, decisions are made based on situations and circumstances, and logic is integrated with emotion as adults develop principles that depend on contexts. One way that we can see the difference between an adult in postformal thought and an adolescent in formal operations is in terms of how they handle emotionally charged issues.

It seems that once we reach adulthood our problem solving abilities change: As we attempt to solve problems, we tend to think more deeply about many areas of our lives, such as relationships, work, and politics (Labouvie-Vief & Diehl, 1999). Because of this, postformal thinkers are able to draw on past experiences to help them solve new problems. Problem-solving strategies using postformal thought vary, depending on the situation. What does this mean? Adults can recognize, for example, that what seems to be an ideal solution to a problem at work involving a disagreement with a colleague may not be the best solution to a disagreement with a significant other.

Explain how you would use your understanding of one of the major developmental theories (psychosexual, psychosocial, or cognitive) to deal with each of the difficulties listed below:

• Your infant daughter puts everything in her mouth, including the dog’s food.
• Your eight-year-old son is failing math; all he cares about is baseball.
• Your two-year-old daughter refuses to wear the clothes you pick for her every morning, which makes getting dressed a twenty-minute battle.
• Your sixty-eight-year-old neighbor is chronically depressed and feels she has wasted her life.
• Your 18-year-old daughter has decided not to go to college. Instead she’s moving to Colorado to become a ski instructor.
• Your 11-year-old son is the class bully.

Theory of Moral Development

A major task beginning in childhood and continuing into adolescence is discerning right from wrong. Psychologist Lawrence Kohlberg (1927–1987) extended upon the foundation that Piaget built regarding cognitive development. Kohlberg believed that moral development, like cognitive development, follows a series of stages. To develop this theory, Kohlberg posed moral dilemmas to people of all ages, and then he analyzed their answers to find evidence of their particular stage of moral development. Before reading about the stages, take a minute to consider how you would answer one of Kohlberg’s best-known moral dilemmas, commonly known as the Heinz dilemma:

In Europe, a woman was near death from a special kind of cancer. There was one drug that the doctors thought might save her. It was a form of radium that a druggist in the same town had recently discovered. The drug was expensive to make, but the druggist was charging ten times what the drug cost him to make. He paid $200 for the radium and charged $2,000 for a small dose of the drug. The sick woman’s husband, Heinz, went to everyone he knew to borrow the money, but he could only get together about $1,000, which is half of what it cost. He told the druggist that his wife was dying and asked him to sell it cheaper or let him pay later. But the druggist said: “No, I discovered the drug and I’m going to make money from it.” So Heinz got desperate and broke into the man’s store to steal the drug for his wife. Should the husband have done that? (Kohlberg, 1969, p. 379)

How would you answer this dilemma? Kohlberg was not interested in whether you answer yes or no to the dilemma: Instead, he was interested in the reasoning behind your answer.

After presenting people with this and various other moral dilemmas, Kohlberg reviewed people’s responses and placed them in different [pb_glossary id="2815"]stages of moral reasoning (Figure 6). According to Kohlberg, an individual progresses from the capacity for pre-conventional morality (before age 9) to the capacity for conventional morality (early adolescence), and toward attaining post-conventional morality (once formal operational thought is attained), which only a few fully achieve. Kohlberg placed in the highest stage responses that reflected the reasoning that Heinz should steal the drug because his wife’s life is more important than the pharmacist making money. The value of a human life overrides the pharmacist’s greed.

It is important to realize that even those people who have the most sophisticated, post-conventional reasons for some choices may make other choices for the simplest of pre-conventional reasons. Many psychologists agree with Kohlberg's theory of moral development but point out that moral reasoning is very different from moral behavior. Sometimes what we say we would do in a situation is not what we actually do in that situation. In other words, we might “talk the talk,” but not “walk the walk.”

How does this theory apply to males and females? Kohlberg (1969) felt that more males than females move past stage four in their moral development. He went on to note that women seem to be deficient in their moral reasoning abilities. These ideas were not well received by Carol Gilligan, a research assistant of Kohlberg, who consequently developed her own ideas of moral development. In her groundbreaking book, In a Different Voice: Psychological Theory and Women’s Development , Gilligan (1982) criticized her former mentor’s theory because it was based only on upper class white men and boys. She argued that women are not deficient in their moral reasoning—she proposed that males and females reason differently. Girls and women focus more on staying connected and the importance of interpersonal relationships. Therefore, in the Heinz dilemma, many girls and women respond that Heinz should not steal the medicine. Their reasoning is that if he steals the medicine, is arrested, and is put in jail, then he and his wife will be separated, and she could die while he is still in prison.

Development in Childhood

Think about the miraculous development that occurs during childhood in order for a tiny zygote to grow into a walking, talking, thinking child. Newborn infants only weigh about 7.5 pounds but their physical, cognitive, and psychosocial skills grow and change as they move through developmental stages. In this section, you'll learn about many of these changes.

• Describe the stages of prenatal development and the significance of prenatal care
• Define and differentiate between various infant reflexes
• Explain the physical, cognitive, and emotional development that occurs from infancy through childhood

Prenatal Development

As discussed at the beginning of this chapter, developmental psychologists often divide our development into three areas: physical development, cognitive development, and psychosocial development. Mirroring Erikson’s stages, lifespan development is divided into different stages that are based on age. We will discuss prenatal, infant, child, adolescent, and adult development.

Germinal Stage (Weeks 1–2)

In the discussion of biopsychology earlier in the book, you learned about genetics and DNA. A mother and father’s DNA is passed on to the child at the moment of conception. Conception occurs when sperm fertilizes an egg and forms a zygote (Figure 7). A zygote begins as a one-cell structure that is created when a sperm and egg merge. The genetic makeup and sex of the baby are set at this point. During the first week after conception, the zygote divides and multiplies, going from a one-cell structure to two cells, then four cells, then eight cells, and so on. This process of cell division is called mitosis. Mitosis  is a fragile process, and fewer than one-half of all zygotes survive beyond the first two weeks (Hall, 2004). After 5 days of mitosis there are 100 cells, and after 9 months there are billions of cells. As the cells divide, they become more specialized, forming different organs and body parts. In the germinal stage, the mass of cells has yet to attach itself to the lining of the mother’s uterus. Once it does, the next stage begins.

Embryonic Stage (Weeks 3–8)

After the zygote divides for about 7–10 days and has 150 cells, it travels down the fallopian tubes and implants itself in the lining of the uterus. Upon implantation, this multi-cellular organism is called an embryo . Now blood vessels grow, forming the placenta. The placenta  is a structure connected to the uterus that provides nourishment and oxygen from the mother to the developing embryo via the umbilical cord. Basic structures of the embryo start to develop into areas that will become the head, chest, and abdomen. During the embryonic stage, the heart begins to beat and organs form and begin to function. The neural tube forms along the back of the embryo, developing into the spinal cord and brain.

Fetal Stage (Weeks 9–40)

When the organism is about nine weeks old, the embryo is called a fetus. At this stage, the fetus is about the size of a kidney bean and begins to take on the recognizable form of a human being as the “tail” begins to disappear.

From 9–12 weeks, the sex organs begin to differentiate. At about 16 weeks, the fetus is approximately 4.5 inches long. Fingers and toes are fully developed, and fingerprints are visible. By the time the fetus reaches the sixth month of development (24 weeks), it weighs up to 1.4 pounds. Hearing has developed, so the fetus can respond to sounds. The internal organs, such as the lungs, heart, stomach, and intestines, have formed enough that a fetus born prematurely at this point has a chance to survive outside of the mother’s womb. Throughout the fetal stage the brain continues to grow and develop, nearly doubling in size from weeks 16 to 28. Around 36 weeks, the fetus is almost ready for birth. It weighs about 6 pounds and is about 18.5 inches long, and by week 37 all of the fetus’s organ systems are developed enough that it could survive outside the mother’s uterus without many of the risks associated with premature birth. The fetus continues to gain weight and grow in length until approximately 40 weeks. By then, the fetus has very little room to move around and birth becomes imminent. The progression through the stages is shown in Figure 8.

Prenatal Influences

During each prenatal stage, genetic and environmental factors can affect development. The developing fetus is completely dependent on the mother for life. It is important that the mother takes good care of herself and receives prenatal care , which is medical care during pregnancy that monitors the health of both the mother and the fetus. According to the National Institutes of Health ([NIH], 2013), routine prenatal care is important because it can reduce the risk of complications to the mother and fetus during pregnancy. In fact, women who are trying to become pregnant or who may become pregnant should discuss pregnancy planning with their doctor. They may be advised, for example, to take a vitamin containing folic acid, which helps prevent certain birth defects, or to monitor aspects of their diet or exercise routines.

Recall that when the zygote attaches to the wall of the mother’s uterus, the placenta is formed. The placenta provides nourishment and oxygen to the fetus. Most everything the mother ingests, including food, liquid, and even medication, travels through the placenta to the fetus, hence the common phrase “eating for two.” Anything the mother is exposed to in the environment affects the fetus; if the mother is exposed to something harmful, the child can show life-long effects.

A teratogen is any environmental agent—biological, chemical, or physical—that causes damage to the developing embryo or fetus. There are different types of teratogens. Alcohol and most drugs cross the placenta and affect the fetus. Alcohol is not safe to drink in any amount during pregnancy. Alcohol use during pregnancy has been found to be the leading preventable cause of mental retardation in children in the United States (Maier & West, 2001). Excessive maternal drinking while pregnant can cause fetal alcohol spectrum disorders with life-long consequences for the child ranging in severity from minor to major (Table 3). Fetal alcohol spectrum disorders (FASD) are a collection of birth defects associated with heavy consumption of alcohol during pregnancy. Physically, children with FASD may have a small head size and abnormal facial features. Cognitively, these children may have poor judgment, poor impulse control, higher rates of ADHD, learning issues, and lower IQ scores. These developmental problems and delays persist into adulthood (Streissguth et al., 2004). Based on studies conducted on animals, it also has been suggested that a mother’s alcohol consumption during pregnancy may predispose her child to like alcohol (Youngentob et al., 2007).

Smoking is also considered a teratogen because nicotine travels through the placenta to the fetus. When the mother smokes, the developing baby experiences a reduction in blood oxygen levels. According to the Centers for Disease Control and Prevention (2013), smoking while pregnant can result in premature birth, low-birth-weight infants, stillbirth, and sudden infant death syndrome (SIDS).

Heroin, cocaine, methamphetamine, almost all prescription medicines, and most over-the counter medications are also considered teratogens. Babies born with a heroin addiction need heroin just like an adult addict. The child will need to be gradually weaned from the heroin under medical supervision; otherwise, the child could have seizures and die. Other teratogens include radiation, viruses such as HIV and herpes, and rubella (German measles). Women in the United States are much less likely to be afflicted with rubella because most women received childhood immunizations or vaccinations that protect the body from disease.

Each organ of the fetus develops during a specific period in the pregnancy, called the critical or sensitive period (Figure 9). For example, research with primate models of FASD has demonstrated that the time during which a developing fetus is exposed to alcohol can dramatically affect the appearance of facial characteristics associated with fetal alcohol syndrome. Specifically, this research suggests that alcohol exposure that is limited to day 19 or 20 of gestation can lead to significant facial abnormalities in the offspring (Ashley, Magnuson, Omnell, & Clarren, 1999). Given regions of the brain also show sensitive periods during which they are most susceptible to the teratogenic effects of alcohol (Tran & Kelly, 2003).

Dig Deeper:  Should Women Who Use Drugs During Pregnancy Be Arrested and Jailed?

As you now know, women who use drugs or alcohol during pregnancy can cause serious lifelong harm to their child. Some people have advocated mandatory screenings for women who are pregnant and have a history of drug abuse, and if the women continue using, to arrest, prosecute, and incarcerate them (Figdor & Kaeser, 1998). This policy was tried in Charleston, South Carolina, as recently as 20 years ago. The policy was called the Interagency Policy on Management of Substance Abuse During Pregnancy, and had disastrous results.

The Interagency Policy applied to patients attending the obstetrics clinic at MUSC, which primarily serves patients who are indigent or on Medicaid. It did not apply to private obstetrical patients. The policy required patient education about the harmful effects of substance abuse during pregnancy. . . . [A] statement also warned patients that protection of unborn and newborn children from the harms of illegal drug abuse could involve the Charleston police, the Solicitor of the Ninth Judicial Court, and the Protective Services Division of the Department of Social Services (DSS). (Jos, Marshall, & Perlmutter, 1995, pp. 120–121)

This policy seemed to deter women from seeking prenatal care, deterred them from seeking other social services, and was applied solely to low-income women, resulting in lawsuits. The program was canceled after 5 years, during which 42 women were arrested. A federal agency later determined that the program involved human experimentation without the approval and oversight of an institutional review board (IRB). What were the flaws in the program and how would you correct them? What are the ethical implications of charging pregnant women with child abuse?

Infancy through Childhood

The average newborn weighs approximately 7.5 pounds. Although small, a newborn is not completely helpless because his reflexes and sensory capacities help him interact with the environment from the moment of birth. All healthy babies are born with newborn reflexes : inborn automatic responses to particular forms of stimulation. Reflexes help the newborn survive until it is capable of more complex behaviors—these reflexes are crucial to survival. They are present in babies whose brains are developing normally and usually disappear around 4–5 months old. Let’s take a look at some of these newborn reflexes. The rooting reflex is the newborn’s response to anything that touches her cheek: When you stroke a baby’s cheek, she naturally turns her head in that direction and begins to suck. The sucking reflex is the automatic, unlearned, sucking motions that infants do with their mouths. Several other interesting newborn reflexes can be observed. For instance, if you put your finger into a newborn’s hand, you will witness the grasping reflex , in which a baby automatically grasps anything that touches his palms. The Moro reflex is the newborn’s response when she feels like she is falling. The baby spreads her arms, pulls them back in, and then (usually) cries. How do you think these reflexes promote survival in the first months of life?

Take a few minutes to view this brief video clip illustrating several newborn reflexes .

If you are interested in learning more about human development in babies, watch  this TED talk by Alison Gopnik . Recent discoveries reveal that babies are probably smarter than we think.

What can young infants see, hear, and smell? Newborn infants’ sensory abilities are significant, but their senses are not yet fully developed. Many of a newborn’s innate preferences facilitate interaction with caregivers and other humans. Although vision is their least developed sense, newborns already show a preference for faces. Babies who are just a few days old also prefer human voices, they will listen to voices longer than sounds that do not involve speech (Vouloumanos & Werker, 2004), and they seem to prefer their mother’s voice over a stranger’s voice (Mills & Melhuish, 1974). In an interesting experiment, 3-week-old babies were given pacifiers that played a recording of the infant’s mother’s voice and of a stranger’s voice. When the infants heard their mother’s voice, they sucked more strongly at the pacifier (Mills & Melhuish, 1974). Newborns also have a strong sense of smell. For instance, newborn babies can distinguish the smell of their own mother from that of others. In a study by MacFarlane (1978), 1-week-old babies who were being breastfed were placed between two gauze pads. One gauze pad was from the bra of a nursing mother who was a stranger, and the other gauze pad was from the bra of the infant’s own mother. More than two-thirds of the week-old babies turned toward the gauze pad with their mother’s scent.

Physical Development

In infancy, toddlerhood, and early childhood, the body’s physical development is rapid (Figure 10). On average, newborns weigh between 5 and 10 pounds, and a newborn’s weight typically doubles in six months and triples in one year. By 2 years old the weight will have quadrupled, so we can expect that a 2 year old should weigh between 20 and 40 pounds. The average length of a newborn is 19.5 inches, increasing to 29.5 inches by 12 months and 34.4 inches by 2 years old (WHO Multicentre Growth Reference Study Group, 2006).

During infancy and childhood, growth does not occur at a steady rate (Carel, Lahlou, Roger, & Chaussain, 2004). Growth slows between 4 and 6 years old: During this time children gain 5–7 pounds and grow about 2–3 inches per year. Once girls reach 8–9 years old, their growth rate outpaces that of boys due to a pubertal growth spurt. This growth spurt continues until around 12 years old, coinciding with the start of the menstrual cycle. By 10 years old, the average girl weighs 88 pounds, and the average boy weighs 85 pounds.

We are born with all of the brain cells that we will ever have—about 100–200 billion neurons (nerve cells) whose function is to store and transmit information (Huttenlocher & Dabholkar, 1997). However, the nervous system continues to grow and develop. Each neural pathway forms thousands of new connections during infancy and toddlerhood. This period of rapid neural growth is called blooming. Neural pathways continue to develop through puberty. The blooming period of neural growth is then followed by a period of pruning, where neural connections are reduced. It is thought that pruning causes the brain to function more efficiently, allowing for mastery of more complex skills (Hutchinson, 2011). Blooming occurs during the first few years of life, and pruning continues through childhood and into adolescence in various areas of the brain.

The size of our brains increases rapidly. For example, the brain of a 2-year-old is 55% of its adult size, and by 6 years old the brain is about 90% of its adult size (Tanner, 1978). During early childhood (ages 3–6), the frontal lobes grow rapidly. Recalling our discussion of the 4 lobes of the brain earlier in this book, the frontal lobes are associated with planning, reasoning, memory, and impulse control. Therefore, by the time children reach school age, they are developmentally capable of controlling their attention and behavior. Through the elementary school years, the frontal, temporal, occipital, and parietal lobes all grow in size. The brain growth spurts experienced in childhood tend to follow Piaget’s sequence of cognitive development, so that significant changes in neural functioning account for cognitive advances (Kolb & Whishaw, 2009; Overman, Bachevalier, Turner, & Peuster, 1992).

Motor development occurs in an orderly sequence as infants move from reflexive reactions (e.g., sucking and rooting) to more advanced motor functioning. For instance, babies first learn to hold their heads up, then to sit with assistance, and then to sit unassisted, followed later by crawling and then walking.

Motor skills refer to our ability to move our bodies and manipulate objects. Fine motor skills focus on the muscles in our fingers, toes, and eyes, and enable coordination of small actions (e.g., grasping a toy, writing with a pencil, and using a spoon). Gross motor skills focus on large muscle groups that control our arms and legs and involve larger movements (e.g., balancing, running, and jumping).

As motor skills develop, there are certain developmental milestones that young children should achieve (Table 4). For each milestone there is an average age, as well as a range of ages in which the milestone should be reached. An example of a developmental milestone is sitting. On average, most babies sit alone at 7 months old. Sitting involves both coordination and muscle strength, and 90% of babies achieve this milestone between 5 and 9 months old. In another example, babies on average are able to hold up their head at 6 weeks old, and 90% of babies achieve this between 3 weeks and 4 months old. If a baby is not holding up his head by 4 months old, he is showing a delay. If the child is displaying delays on several milestones, that is reason for concern, and the parent or caregiver should discuss this with the child’s pediatrician. Some developmental delays can be identified and addressed through early intervention.

Cognitive Development

In addition to rapid physical growth, young children also exhibit significant development of their cognitive abilities. Piaget thought that children’s ability to understand objects—such as learning that a rattle makes a noise when shaken—was a cognitive skill that develops slowly as a child matures and interacts with the environment. Today, developmental psychologists think Piaget was incorrect. Researchers have found that even very young children understand objects and how they work long before they have experience with those objects (Baillargeon, 1987; Baillargeon, Li, Gertner, & Wu, 2011). For example, children as young as 3 months old demonstrated knowledge of the properties of objects that they had only viewed and did not have prior experience with them. In one study, 3-month-old infants were shown a truck rolling down a track and behind a screen. The box, which appeared solid but was actually hollow, was placed next to the track. The truck rolled past the box as would be expected. Then the box was placed on the track to block the path of the truck. When the truck was rolled down the track this time, it continued unimpeded. The infants spent significantly more time looking at this impossible event (Figure 11). Baillargeon (1987) concluded that they knew solid objects cannot pass through each other. Baillargeon’s findings suggest that very young children have an understanding of objects and how they work, which Piaget (1954) would have said is beyond their cognitive abilities due to their limited experiences in the world.

Just as there are physical milestones that we expect children to reach, there are also cognitive milestones. It is helpful to be aware of these milestones as children gain new abilities to think, problem solve, and communicate. For example, infants shake their head “no” around 6–9 months, and they respond to verbal requests to do things like “wave bye-bye” or “blow a kiss” around 9–12 months. Remember Piaget’s ideas about object permanence? We can expect children to grasp the concept that objects continue to exist even when they are not in sight by around 8 months old. Because toddlers (i.e., 12–24 months old) have mastered object permanence, they enjoy games like hide and seek, and they realize that when someone leaves the room they will come back (Loop, 2013). Toddlers also point to pictures in books and look in appropriate places when you ask them to find objects.

Preschool-age children (i.e., 3–5 years old) also make steady progress in cognitive development. Not only can they count, name colors, and tell you their name and age, but they can also make some decisions on their own, such as choosing an outfit to wear. Preschool-age children understand basic time concepts and sequencing (e.g., before and after), and they can predict what will happen next in a story. They also begin to enjoy the use of humor in stories. Because they can think symbolically, they enjoy pretend play and inventing elaborate characters and scenarios. One of the most common examples of their cognitive growth is their blossoming curiosity. Preschool-age children love to ask “Why?”

An important cognitive change occurs in children this age. Recall that Piaget described 2–3 year olds as egocentric, meaning that they do not have an awareness of others’ points of view. Between 3 and 5 years old, children come to understand that people have thoughts, feelings, and beliefs that are different from their own. This is known as theory-of-mind (TOM). Children can use this skill to tease others, persuade their parents to purchase a candy bar, or understand why a sibling might be angry. When children develop TOM, they can recognize that others have false beliefs (Dennett, 1987; Callaghan et al., 2005).

False-belief tasks are useful in determining a child’s acquisition of theory-of-mind (TOM). Take a look at this video clip showing a false-belief task involving a box of crayons.

You can view the transcript for "The "False Belief" Test: Theory of Mind" here (opens in new window) .

Cognitive skills continue to expand in middle and late childhood (6–11 years old). Thought processes become more logical and organized when dealing with concrete information (Figure 12). Children at this age understand concepts such as the past, present, and future, giving them the ability to plan and work toward goals. Additionally, they can process complex ideas such as addition and subtraction and cause-and-effect relationships. However, children’s attention spans tend to be very limited until they are around 11 years old. After that point, it begins to improve through adulthood.

One well-researched aspect of cognitive development is language acquisition. As mentioned earlier, the order in which children learn language structures is consistent across children and cultures (Hatch, 1983). You’ve also learned that some psychological researchers have proposed that children possess a biological predisposition for language acquisition.

Starting before birth, babies begin to develop language and communication skills. At birth, babies apparently recognize their mother’s voice and can discriminate between the language(s) spoken by their mothers and foreign languages, and they show preferences for faces that are moving in synchrony with audible language (Blossom & Morgan, 2006; Pickens, 1994; Spelke & Cortelyou, 1981).

Children communicate information through gesturing long before they speak, and there is some evidence that gesture usage predicts subsequent language development (Iverson & Goldin-Meadow, 2005). In terms of producing spoken language, babies begin to coo almost immediately. Cooing is a one-syllable combination of a consonant and a vowel sound (e.g., coo or ba). Interestingly, babies replicate sounds from their own languages. A baby whose parents speak French will coo in a different tone than a baby whose parents speak Spanish or Urdu. After cooing, the baby starts to babble. Babbling begins with repeating a syllable, such as ma-ma, da-da, or ba-ba. When a baby is about 12 months old, we expect her to say her first word for meaning, and to start combining words for meaning at about 18 months.

At about 2 years old, a toddler uses between 50 and 200 words; by 3 years old they have a vocabulary of up to 1,000 words and can speak in sentences. During the early childhood years, children's vocabulary increases at a rapid pace. This is sometimes referred to as the “vocabulary spurt” and has been claimed to involve an expansion in vocabulary at a rate of 10–20 new words per week. Recent research may indicate that while some children experience these spurts, it is far from universal (as discussed in Ganger & Brent, 2004). It has been estimated that, 5 year olds understand about 6,000 words, speak 2,000 words, and can define words and question their meanings. They can rhyme and name the days of the week. Seven year olds speak fluently and use slang and clichés (Stork & Widdowson, 1974).

What accounts for such dramatic language learning by children? Behaviorist B. F. Skinner thought that we learn language in response to reinforcement or feedback, such as through parental approval or through being understood. For example, when a two-year-old child asks for juice, he might say, “me juice,” to which his mother might respond by giving him a cup of apple juice. Noam Chomsky (1957) criticized Skinner’s theory and proposed that we are all born with an innate capacity to learn language. Chomsky called this mechanism a language acquisition device (LAD). Who is correct? Both Chomsky and Skinner are right. Remember that we are a product of both nature and nurture. Researchers now believe that language acquisition is partially inborn and partially learned through our interactions with our linguistic environment (Gleitman & Newport, 1995; Stork & Widdowson, 1974).

Everyday Connection: The Importance of Play and Recess

According to the American Academy of Pediatrics (2007), unstructured play is an integral part of a child’s development. It builds creativity, problem solving skills, and social relationships. Play also allows children to develop a theory-of-mind as they imaginatively take on the perspective of others.

Outdoor play allows children the opportunity to directly experience and sense the world around them. While doing so, they may collect objects that they come across and develop lifelong interests and hobbies. They also benefit from increased exercise, and engaging in outdoor play can actually increase how much they enjoy physical activity. This helps support the development of a healthy heart and brain. Unfortunately, research suggests that today’s children are engaging in less and less outdoor play (Clements, 2004). Perhaps, it is no surprise to learn that lowered levels of physical activity in conjunction with easy access to calorie-dense foods with little nutritional value are contributing to alarming levels of childhood obesity (Karnik & Kanekar, 2012).

Despite the adverse consequences associated with reduced play, some children are over scheduled and have little free time to engage in unstructured play. In addition, some schools have taken away recess time for children in a push for students to do better on standardized tests, and many schools commonly use loss of recess as a form of punishment. Do you agree with these practices? Why or why not?

Psychosocial development occurs as children form relationships, interact with others, and understand and manage their feelings. In social and emotional development, forming healthy attachments is very important and is the major social milestone of infancy. Attachment  is a long-standing connection or bond with others. Developmental psychologists are interested in how infants reach this milestone. They ask such questions as: How do parent and infant attachment bonds form? How does neglect affect these bonds? What accounts for children’s attachment differences?

Building on the work of Harlow and others, John Bowlby developed the concept of attachment theory. He defined attachment as the affectional bond or tie that an infant forms with the mother (Bowlby, 1969). An infant must form this bond with a primary caregiver in order to have normal social and emotional development. In addition, Bowlby proposed that this attachment bond is very powerful and continues throughout life. He used the concept of secure base to define a healthy attachment between parent and child (1988). A secure base is a parental presence that gives the child a sense of safety as he explores his surroundings. Bowlby said that two things are needed for a healthy attachment: The caregiver must be responsive to the child’s physical, social, and emotional needs; and the caregiver and child must engage in mutually enjoyable interactions (Bowlby, 1969) (Figure 13).

While Bowlby thought attachment was an all-or-nothing process, Mary Ainsworth’s (1970) research showed otherwise. Ainsworth wanted to know if children differ in the ways they bond, and if so, why. To find the answers, she used the Strange Situation procedure to study attachment between mothers and their infants (1970). In the Strange Situation, the mother (or primary caregiver) and the infant (age 12-18 months) are placed in a room together. There are toys in the room, and the caregiver and child spend some time alone in the room. After the child has had time to explore her surroundings, a stranger enters the room. The mother then leaves her baby with the stranger. After a few minutes, she returns to comfort her child.

Based on how the infants/toddlers responded to the separation and reunion, Ainsworth identified three types of parent-child attachments: secure, avoidant, and resistant (Ainsworth & Bell, 1970). A fourth style, known as disorganized attachment, was later described (Main & Solomon, 1990). The most common type of attachment—also considered the healthiest—is called secure attachment (Figure 14). In this type of attachment, the toddler prefers his parent over a stranger. The attachment figure is used as a secure base to explore the environment and is sought out in times of stress. Securely attached children were distressed when their caregivers left the room in the Strange Situation experiment, but when their caregivers returned, the securely attached children were happy to see them. Securely attached children have caregivers who are sensitive and responsive to their needs.

With avoidant attachment   (sometimes called insecure or anxious-avoidant), the child is unresponsive to the parent, does not use the parent as a secure base, and does not care if the parent leaves. The toddler reacts to the parent the same way she reacts to a stranger. When the parent does return, the child is slow to show a positive reaction. Ainsworth theorized that these children were most likely to have a caregiver who was insensitive and inattentive to their needs (Ainsworth, Blehar, Waters, & Wall, 1978).

In cases of resistant attachment (also called ambivalent or anxious-ambivalent/resistant), children tend to show clingy behavior, but then they reject the attachment figure’s attempts to interact with them (Ainsworth & Bell, 1970). These children do not explore the toys in the room, as they are too fearful. During separation in the Strange Situation, they became extremely disturbed and angry with the parent. When the parent returns, the children are difficult to comfort. Resistant attachment is the result of the caregivers’ inconsistent level of response to their child.

Finally, children with disorganized attachment  behaved oddly in the Strange Situation. They freeze, run around the room in an erratic manner, or try to run away when the caregiver returns (Main & Solomon, 1990). This type of attachment is seen most often in kids who have been abused. Research has shown that abuse disrupts a child’s ability to regulate their emotions.

While Ainsworth’s research has found support in subsequent studies, it has also met criticism. Some researchers have pointed out that a child’s temperament may have a strong influence on attachment (Gervai, 2009; Harris, 2009), and others have noted that attachment varies from culture to culture, a factor not accounted for in Ainsworth’s research (Rothbaum, Weisz, Pott, Miyake, & Morelli, 2000; van Ijzendoorn & Sagi-Schwartz, 2008).

Watch this video to view a clip of the Strange Situation. Try to identify which type of attachment baby Lisa exhibits.

You can view the transcript for "The Strange Situation - Mary Ainsworth" here (opens in new window) .

Self-Concept

Just as attachment is the main psychosocial milestone of infancy, the primary psychosocial milestone of childhood is the development of a positive sense of self. How does self-awareness develop? Infants don’t have a self-concept, which is an understanding of who they are. If you place a baby in front of a mirror, she will reach out to touch her image, thinking it is another baby. However, by about 18 months a toddler will recognize that the person in the mirror is herself. How do we know this? In a well-known experiment, a researcher placed a red dot of paint on children’s noses before putting them in front of a mirror (Amsterdam, 1972). Commonly known as the mirror test, this behavior is demonstrated by humans and a few other species and is considered evidence of self-recognition (Archer, 1992). At 18 months old they would touch their own noses when they saw the paint, surprised to see a spot on their faces. By 24–36 months old children can name and/or point to themselves in pictures, clearly indicating self-recognition.

Children from 2–4 years old display a great increase in social behavior once they have established a self-concept. They enjoy playing with other children, but they have difficulty sharing their possessions. Also, through play children explore and come to understand their gender roles and can label themselves as a girl or boy (Chick, Heilman-Houser, & Hunter, 2002). By 4 years old, children can cooperate with other children, share when asked, and separate from parents with little anxiety. Children at this age also exhibit autonomy, initiate tasks, and carry out plans. Success in these areas contributes to a positive sense of self. Once children reach 6 years old, they can identify themselves in terms of group memberships: “I’m a first grader!” School-age children compare themselves to their peers and discover that they are competent in some areas and less so in others (recall Erikson’s task of industry versus inferiority). At this age, children recognize their own personality traits as well as some other traits they would like to have. For example, 10-year-old Layla says, “I’m kind of shy. I wish I could be more talkative like my friend Alexa.”

Development of a positive self-concept is important to healthy development. Children with a positive self-concept tend to be more confident, do better in school, act more independently, and are more willing to try new activities (Maccoby, 1980; Ferrer & Fugate, 2003). Formation of a positive self-concept begins in Erikson’s toddlerhood stage, when children establish autonomy and become confident in their abilities. Development of self-concept continues in elementary school, when children compare themselves to others. When the comparison is favorable, children feel a sense of competence and are motivated to work harder and accomplish more. Self-concept is re-evaluated in Erikson’s adolescence stage, as teens form an identity. They internalize the messages they have received regarding their strengths and weaknesses, keeping some messages and rejecting others. Adolescents who have achieved identity formation are capable of contributing positively to society (Erikson, 1968).

What can parents do to nurture a healthy self-concept? Diana Baumrind (1971, 1991) thinks parenting style may be a factor. The way we parent is an important factor in a child’s socioemotional growth. Baumrind developed and refined a theory describing four parenting styles: authoritative, authoritarian, permissive, and uninvolved. With the authoritative style , the parent gives reasonable demands and consistent limits, expresses warmth and affection, and listens to the child’s point of view. Parents set rules and explain the reasons behind them. They are also flexible and willing to make exceptions to the rules in certain cases—for example, temporarily relaxing bedtime rules to allow for a nighttime swim during a family vacation. Of the four parenting styles, the authoritative style is the one that is most encouraged in modern American society. American children raised by authoritative parents tend to have high self-esteem and social skills. However, effective parenting styles vary as a function of culture and, as Small (1999) points out, the authoritative style is not necessarily preferred or appropriate in all cultures.

In authoritarian style , the parent places high value on conformity and obedience. The parents are often strict, tightly monitor their children, and express little warmth. In contrast to the authoritative style, authoritarian parents probably would not relax bedtime rules during a vacation because they consider the rules to be set, and they expect obedience. This style can create anxious, withdrawn, and unhappy kids. However, it is important to point out that authoritarian parenting is as beneficial as the authoritative style in some ethnic groups (Russell, Crockett, & Chao, 2010). For instance, first-generation Chinese American children raised by authoritarian parents did just as well in school as their peers who were raised by authoritative parents (Russell et al., 2010).

For parents who employ the permissive style  of parenting, the kids run the show and anything goes. Permissive parents make few demands and rarely use punishment. They tend to be very nurturing and loving, and may play the role of friend rather than parent. In terms of our example of vacation bedtimes, permissive parents might not have bedtime rules at all—instead they allow the child to choose his bedtime whether on vacation or not. Not surprisingly, children raised by permissive parents tend to lack self-discipline, and the permissive parenting style is negatively associated with grades (Dornbusch, Ritter, Leiderman, Roberts, & Fraleigh, 1987). The permissive style may also contribute to other risky behaviors such as alcohol abuse (Bahr & Hoffman, 2010), risky sexual behavior especially among female children (Donenberg, Wilson, Emerson, & Bryant, 2002), and increased display of disruptive behaviors by male children (Parent et al., 2011). However, there are some positive outcomes associated with children raised by permissive parents. They tend to have higher self-esteem, better social skills, and report lower levels of depression (Darling, 1999).

With the uninvolved style  of parenting, the parents are indifferent, uninvolved, and sometimes referred to as neglectful. They don’t respond to the child’s needs and make relatively few demands. This could be because of severe depression or substance abuse, or other factors such as the parents’ extreme focus on work. These parents may provide for the child’s basic needs, but little else. The children raised in this parenting style are usually emotionally withdrawn, fearful, anxious, perform poorly in school, and are at an increased risk of substance abuse (Darling, 1999).

As you can see, parenting styles influence childhood adjustment, but could a child’s temperament likewise influence parenting? Temperament refers to innate traits that influence how one thinks, behaves, and reacts with the environment. Children with easy temperaments demonstrate positive emotions, adapt well to change, and are capable of regulating their emotions. Conversely, children with difficult temperaments demonstrate negative emotions and have difficulty adapting to change and regulating their emotions. Difficult children are much more likely to challenge parents, teachers, and other caregivers (Thomas, 1984). Therefore, it’s possible that easy children (i.e., social, adaptable, and easy to soothe) tend to elicit warm and responsive parenting, while demanding, irritable, withdrawn children evoke irritation in their parents or cause their parents to withdraw (Sanson & Rothbart, 1995).

Development in Adolescence and Adulthood

Changes in development during childhood are rapid and more obvious than the changes that come later on in life, but before you reach adulthood, there is one more large transition: adolescence. Adolescence brings the physical development of puberty, as well as cognitive, social, and emotional changes. Following adolescence, transitions are less obvious, but still significant throughout emerging adulthood and adulthood. Finally, growing older means confronting many psychological, emotional, and social issues that come with entering the last phase of life.

Watch this video from a few of the world's oldest people for some advice on how you can also live a fulfilling life until the very end.

You can view the transcript for "How to Be the Oldest Person Alive" here (opens in new window) .

• Describe physical, cognitive, and emotional development that occurs during adolescence
• Describe physical, cognitive, and emotional development that occurs in adulthood
• Differentiate between fluid and crystallized intelligence

Adolescence

Adolescence is a socially constructed concept. In pre-industrial society, children were considered adults when they reached physical maturity, but today we have an extended time between childhood and adulthood called adolescence. Adolescence is the period of development that begins at puberty and ends at emerging adulthood, or into the mid- to late 20s. In the United States, adolescence is seen as a time to develop independence from parents while remaining connected to them (Figure 15). The typical age range of adolescence is from 12 to 18 years, and this stage of development also has some predictable physical, cognitive, and psychosocial milestones.

As noted above, adolescence begins with puberty. While the sequence of physical changes in puberty is predictable, the onset and pace of puberty vary widely. Several physical changes occur during puberty, such as adrenarche and gonadarche, the maturing of the adrenal glands and sex glands, respectively. Also during this time, primary and secondary sexual characteristics develop and mature. Primary sexual characteristics are organs specifically needed for reproduction, like the uterus and ovaries in females and testes in males. Secondary sexual characteristics are physical signs of sexual maturation that do not directly involve sex organs, such as development of breasts and hips in girls, and development of facial hair and a deepened voice in boys. Girls experience menarche, the beginning of menstrual periods, usually around 12–13 years old, and boys experience spermarche, the first ejaculation, around 13–14 years old.

During puberty, both sexes experience a rapid increase in height (i.e., growth spurt). For girls this begins between 8 and 13 years old, with adult height reached between 10 and 16 years old. Boys begin their growth spurt slightly later, usually between 10 and 16 years old, and reach their adult height between 13 and 17 years old. Both nature (i.e., genes) and nurture (e.g., nutrition, medications, and medical conditions) can influence height.

Because rates of physical development vary so widely among teenagers, puberty can be a source of pride or embarrassment. Early maturing boys tend to be stronger, taller, and more athletic than their later maturing peers. They are usually more popular, confident, and independent, but they are also at a greater risk for substance abuse and early sexual activity (Flannery, Rowe, & Gulley, 1993; Kaltiala-Heino, Rimpela, Rissanen, & Rantanen, 2001). Early maturing girls may be teased or overtly admired, which can cause them to feel self-conscious about their developing bodies. These girls are at a higher risk for depression, substance abuse, and eating disorders (Ge, Conger, & Elder, 2001; Graber, Lewinsohn, Seeley, & Brooks-Gunn, 1997; Striegel-Moore & Cachelin, 1999). Late blooming boys and girls (i.e., they develop more slowly than their peers) may feel self-conscious about their lack of physical development. Negative feelings are particularly a problem for late maturing boys, who are at a higher risk for depression and conflict with parents (Graber et al., 1997) and more likely to be bullied (Pollack & Shuster, 2000).

The adolescent brain also remains under development. Recall from your earlier study, that the brain consists of six regions: temporal lobe, brain stem, cerebellum, occipital lobe (includes the visual cortex), parietal lobe, and the frontal lobe. The frontal lobe consists of the prefrontal cortex, premotor cortex, and motor cortex. The prefrontal lobe lies just behind the forehead. Up until puberty, brain cells continue to bloom in the frontal region. Adolescents engage in increased risk-taking behaviors and emotional outbursts possibly because the frontal lobes of their brains are still developing (Figure 16). Recall that this area is often called the "CEO of the brain", as it is responsible for judgment, impulse control, and planning. It is still maturing into early adulthood, up until around age 25 (Casey, Tottenham, Liston, & Durston, 2005).

Brain maturity occurs when there is growth of new neural connections and the pruning of unused neurons and connections. According to recent research, the brain regions tend to develop from the back to the front of the brain. Also, myelin continues to grow around axons and neurons helping to speed transmission between the various regions of the brain.

Psychosocial Development

Adolescents continue to refine their sense of self as they relate to others. Erikson referred to the task of the adolescent as one of identity versus role confusion. Thus, in Erikson’s view, an adolescent’s main questions are “Who am I?” and “Who do I want to be?” Some adolescents adopt the values and roles that their parents expect for them. Other teens develop identities that are in opposition to their parents but align with a peer group. This is common as peer relationships become a central focus in adolescents’ lives.

As adolescents work to form their identities, they pull away from their parents, and the peer group becomes very important (Shanahan, McHale, Osgood, & Crouter, 2007). Despite spending less time with their parents, most teens report positive feelings toward them (Moore, Guzman, Hair, Lippman, & Garrett, 2004). Warm and healthy parent-child relationships have been associated with positive child outcomes, such as better grades and fewer school behavior problems, in the United States as well as in other countries (Hair et al., 2005).

It appears that most teens don’t experience adolescent storm and stress to the degree once famously suggested by G. Stanley Hall, a pioneer in the study of adolescent development. Only small numbers of teens have major conflicts with their parents (Steinberg & Morris, 2001), and most disagreements are minor. For example, in a study of over 1,800 parents of adolescents from various cultural and ethnic groups, Barber (1994) found that conflicts occurred over day-to-day issues such as homework, money, curfews, clothing, chores, and friends. These types of arguments tend to decrease as teens develop (Galambos & Almeida, 1992).

Emerging Adulthood

The next stage of development is emerging adulthood . This is a relatively newly defined period of lifespan development spanning from 18 years old to the mid-20s, characterized as an in-between time where identity exploration is focused on work and love.

When does a person become an adult? There are many ways to answer this question. In the United States, you are legally considered an adult at 18 years old. But other definitions of adulthood vary widely; in sociology, for example, a person may be considered an adult when she becomes self-supporting, chooses a career, gets married, or starts a family. The ages at which we achieve these milestones vary from person to person as well as from culture to culture. For example, in the African country of Malawi, 15-year-old Njemile was married at 14 years old and had her first child at 15 years old. In her culture she is considered an adult. Children in Malawi take on adult responsibilities such as marriage and work (e.g., carrying water, tending babies, and working fields) as early as 10 years old. In stark contrast, independence in Western cultures is taking longer and longer, effectively delaying the onset of adult life.

Why is it taking twenty-somethings so long to grow up? It seems that emerging adulthood is a product of both Western culture and our current times (Arnett, 2000). People in developed countries are living longer, allowing the freedom to take an extra decade to start a career and family. Changes in the workforce also play a role. For example, 50 years ago, a young adult with a high school diploma could immediately enter the work force and climb the corporate ladder. That is no longer the case. Bachelor’s and even graduate degrees are required more and more often—even for entry-level jobs (Arnett, 2000). In addition, many students are taking longer (five or six years) to complete a college degree as a result of working and going to school at the same time. After graduation, many young adults return to the family home because they have difficulty finding a job. Changing cultural expectations may be the most important reason for the delay in entering adult roles. Young people are spending more time exploring their options, so they are delaying marriage and work as they change majors and jobs multiple times, putting them on a much later timetable than their parents (Arnett, 2000).

Adulthood begins around 20 years old and has three distinct stages: early, middle, and late. Each stage brings its own set of rewards and challenges.

By the time we reach early adulthood (20 to early 40s), our physical maturation is complete, although our height and weight may increase slightly. In young adulthood, our physical abilities are at their peak, including muscle strength, reaction time, sensory abilities, and cardiac functioning. Most professional athletes are at the top of their game during this stage. Many women have children in the young adulthood years, so they may see additional weight gain and breast changes.

Middle adulthood extends from the 40s to the 60s (Figure 18). Physical decline is gradual. The skin loses some elasticity, and wrinkles are among the first signs of aging. Visual acuity decreases during this time. Women experience a gradual decline in fertility as they approach the onset of menopause, the end of the menstrual cycle, around 50 years old. Both men and women tend to gain weight: in the abdominal area for men and in the hips and thighs for women. Hair begins to thin and turn gray.

Late adulthood is considered to extend from the 60s on. This is the last stage of physical change. The skin continues to lose elasticity, reaction time slows further, and muscle strength diminishes. Smell, taste, hearing, and vision, so sharp in our twenties, decline significantly. The brain may also no longer function at optimal levels, leading to problems like memory loss, dementia, and Alzheimer’s disease in later years.

Because we spend so many years in adulthood (more than any other stage), cognitive changes are numerous. In fact, research suggests that adult cognitive development is a complex, ever changing process that may be even more active than cognitive development in infancy and early childhood (Fischer, Yan, & Stewart, 2003).

Researchers have identified areas of both losses and gains in cognition in older age. Cognitive ability and intelligence are often measured using standardized tests and validated measures. The psychometric approach has identified two categories of intelligence that show different rates of change across the life span (Schaie & Willis, 1996). Fluid intelligence  refers to information processing abilities, such as logical reasoning, remembering lists, spatial ability, and reaction time. Crystallized intelligence  encompasses abilities that draw upon experience and knowledge. Measures of crystallized intelligence include vocabulary tests, solving number problems, and understanding texts.

With age, systematic declines are observed on cognitive tasks requiring self-initiated, effortful processing, without the aid of supportive memory cues (Park, 2000). Older adults tend to perform poorer than young adults on memory tasks that involve recall of information, where individuals must retrieve information they learned previously without the help of a list of possible choices. For example, older adults may have more difficulty recalling facts such as names or contextual details about where or when something happened (Craik, 2000). What might explain these deficits as we age? As we age, working memory, or our ability to simultaneously store and use information, becomes less efficient (Craik & Bialystok, 2006). The ability to process information quickly also decreases with age. This slowing of processing speed may explain age differences on many different cognitive tasks (Salthouse, 2004). Some researchers have argued that inhibitory functioning, or the ability to focus on certain information while suppressing attention to less pertinent information, declines with age and may explain age differences in performance on cognitive tasks (Hasher & Zacks, 1988). Finally, it is well established that our hearing and vision decline as we age. Longitudinal research has proposed that deficits in sensory functioning explain age differences in a variety of cognitive abilities (Baltes & Lindenberger, 1997).

Fewer age differences are observed when memory cues are available, such as for recognition memory tasks, or when individuals can draw upon acquired knowledge or experience. For example, older adults often perform as well if not better than young adults on tests of word knowledge or vocabulary. With age often comes expertise, and research has pointed to areas where aging experts perform as well or better than younger individuals. For example, older typists were found to compensate for age-related declines in speed by looking farther ahead at printed text (Salthouse, 1984). Compared to younger players, older chess experts are able to focus on a smaller set of possible moves, leading to greater cognitive efficiency (Charness, 1981). Accrued knowledge of everyday tasks, such as grocery prices, can help older adults to make better decisions than young adults (Tentori, Osheron, Hasher, & May, 2001).

How do changes or maintenance of cognitive ability affect older adults’ everyday lives? Researchers have studied cognition in the context of several different everyday activities. One example is driving. Although older adults often have more years of driving experience, cognitive declines related to reaction time or attentional processes may pose limitations under certain circumstances (Park & Gutchess, 2000). Research on interpersonal problem solving suggested that older adults use more effective strategies than younger adults to navigate through social and emotional problems (Blanchard-Fields, 2007). In the context of work, researchers rarely find that older individuals perform poorer on the job (Park & Gutchess, 2000). Similar to everyday problem solving, older workers may develop more efficient strategies and rely on expertise to compensate for cognitive decline.

How can we delay the onset of cognitive decline? Mental and physical activity seems to play a part (Figure 20). Research has found adults who engage in mentally and physically stimulating activities experience less cognitive decline and have a reduced incidence of mild cognitive impairment and dementia (Hertzog, Kramer, Wilson, & Lindenberger, 2009; Larson et al., 2006; Podewils et al., 2005).

There are many theories about the social and emotional aspects of aging. Some aspects of healthy aging include activities, social connectedness, and the role of a person’s culture. According to many theorists, including George Vaillant (2002), who studied and analyzed over 50 years of data, we need to have and continue to find meaning throughout our lives. For those in early and middle adulthood, meaning is found through work (Sterns & Huyck, 2001) and family life (Markus, Ryff, Curan, & Palmersheim, 2004). These areas relate to the tasks that Erikson referred to as intimacy versus isolation in early adulthood and  generativity versus stagnation  in middle adulthood. As mentioned previously, adults tend to define themselves by what they do—their careers. Earnings peak during this time, yet job satisfaction is more closely tied to work that involves contact with other people, is interesting, provides opportunities for advancement, and allows some independence (Mohr & Zoghi, 2006) than it is to salary (Iyengar, Wells, & Schwartz, 2006). How might being unemployed or being in a dead-end job challenge adult well-being?

As people enter the final stages of life, they have what Erik Erikson described as a crisis over integrity versus despair. In other words, they review the events of their lives and try to come to terms with the mark (or lack thereof) that they have made on the world. People who believe they have had a positive impact on the world through their contributions live the end of life with a sense of integrity. Those who feel they have not measured up to certain standards—either their own or others'—develop a sense of despair.

Positive relationships with significant others in our adult years have been found to contribute to a state of well-being (Ryff & Singer, 2009). Most adults in the United States identify themselves through their relationships with family—particularly with spouses, children, and parents (Markus et al., 2004). While raising children can be stressful, especially when they are young, research suggests that parents reap the rewards down the road, as adult children tend to have a positive effect on parental well-being (Umberson, Pudrovska, & Reczek, 2010). Having a stable marriage has also been found to contribute to well-being throughout adulthood (Vaillant, 2002).

Another aspect of positive aging is believed to be social connectedness and social support. As we get older, socioemotional selectivity theory suggests that our social support and friendships dwindle in number, but remain as close, if not more close than in our earlier years (Carstensen, 1992) (Figure 21).

Putting It Together: Lifespan Development

In this chapter, you learned to

• compare and contrast theories lifespan development theories
• explain the physical, cognitive, and emotional development that occurs from infancy through childhood
• describe physical, cognitive, and emotional development in adolescence and adulthood

Our understanding of human nature has come a long way since the belief that children were just little adults in need of instruction. Through ongoing research, we now know that children hit certain milestones that enable them to take another viewpoint or understand the law of conservation, that babies can understand enough about the world around them to make moral judgments, and that issues of physical, social, and cognitive importance change across the lifespan.

Adolescence is one of the time periods of interest to psychologists, especially due to the focus on identity formation, which often involves a period of exploration followed by commitments to particular identities. Adolescence is characterized by risky behavior, which is made more likely by changes in the brain in which reward-processing centers develop more rapidly than cognitive control systems, making adolescents more sensitive to rewards than to possible negative consequences.

Marcia (1966) described identify formation during adolescence as involving both decision points and commitments with respect to ideologies (e.g., religion, politics) and occupations. He described four identity statuses: foreclosure, identity diffusion, moratorium, and identity achievement.

• Foreclosure occurs when an individual commits to an identity without exploring options.
• Identity diffusion occurs when adolescents neither explore nor commit to any identities.
• Moratorium is a state in which adolescents are actively exploring options but have not yet made commitments.
• Identity achievement occurs when individuals have explored different options and then made identity commitments.

Think about your own adolescent experience (you may consider yourself still in this life stage). Which identity status best fits with your own experience? Do you feel committed to your current identity, or do you feel as though you are still developing? Regardless of your answer, you can rest assured that human development does not end with adolescence, and research proves that people can continue to learn, grow, and even change as long as they would like.

Ainsworth, M. D. S., & Bell, S. M. (1970). Attachment, exploration, and separation: Illustrated by the behavior of one-year-olds in a strange situation. Child Development, 41, 49–67.

Ainsworth, M. D. S., Blehar, M. C., Waters, E., & Wall, S. (1978). Patterns of attachment: A psychological study of the strange situation. Hillsdale, NJ: Erlbaum.

American Academy of Pediatrics. (2007). The importance of play in promoting healthy child development and maintaining strong parent-child bonds. Pediatrics, 199(1), 182–191.

Amsterdam, B. (1972). Mirror image reactions before age two. Developmental Psychobiology, 5, 297–305.

Archer, J. (1992). Ethology and human development. New York, NY: Harvester Wheatsheaf.

Arnett, J. (2000). Emerging adulthood: A theory of development from the late teens through the twenties. American Psychologist, 55(5), 469–480.

Ashley, S. J., Magnuson, S. I., Omnell, L. M., & Clarren, S. K. (1999). Fetal alcohol syndrome: Changes in craniofacial form with age, cognition, and timing of ethanol exposure in the macaque. Teratology, 59(3), 163–172.

Bahr, S. J., & Hoffman, J. P. (2010). Parenting style, religiosity, peers, and adolescent heavy drinking. Journal of Studies on Alcohol and Drugs, 71, 539–543.

Baillargeon, R. (2004). Infants’ reasoning about hidden objects: Evidence for event-general and event-specific expectations. Developmental Science, 7(4), 391–424.

Baillargeon, R. (1987). Young infants' reasoning about the physical and spatial properties of a hidden object. Cognitive Development, 2(3), 179–200.

Baillargeon, R., Li, J., Gertner, Y., & Wu, D. (2011). How do infants reason about physical events. The Wiley-Blackwell handbook of childhood cognitive development, 2, 11–48.

Baltes, P. B . (1987). Theoretical propositions of lifespan developmental psychology: On the dynamics between growth and decline. Developmental Psychology, 23, 611–626.

Baltes, P. B. & Lindenberger, U. (1997). Emergence of powerful connection between sensory and cognitive functions across the adult life span: A new window to the study of cognitive aging?  Psychology and Aging, 12 , 12–21.

Barber, B. K. (1994). Cultural, family, and person contexts of parent-adolescent conflict. Journal of Marriage and the Family, 56, 375–386.

Basseches, M. (1984). Dialectical thinking as metasystematic form of cognitive organization. In M. L. Commons, F. A. Richards, & C. Armon (Eds.), Beyond formal operations: Late adolescent and adult cognitive development (pp. 216–238). New York, NY: Praeger.

Baumrind, D. (1971). Current patterns of parental authority. Developmental Psychology, 4(1, Pt. 2), 1–103. doi:10.1037/h0030372

Baumrind, D. (1991). The influence of parenting style on adolescent competence and substance use. Journal of Early Adolescence, 11(1), 56–95.

Bayley, N., & Oden, M. H. (1955). The maintenance of intellectual ability in gifted adults. Journal of Gerontology, 10, 91–107.

Bjorklund, D. F. (1987). A note on neonatal imitation. Developmental Review, 7, 86–92.

Blanchard-Fields, F. (2007). Everyday problem solving and emotion: An adult development perspective. Current Directions in Psychological Science, 16, 26–31.

Blossom, M., & Morgan, J.L. (2006). Does the face say what the mouth says? A study of infants’ sensitivity to visual prosody. In 30th anuual Boston University conference on language development, Somerville, MA.

Bogartz, R. S., Shinskey, J. L., & Schilling, T. (2000). Infancy, 1(4), 403–428.

Bowlby, J. (1969). Attachment and loss: Attachment (Vol. 1). New York, NY: Basic Books.

Bowlby, J. (1988). A secure base: Parent-child attachment and health human development. New York, NY: Basic Books.

Brumley, R., Enquidanos, S., Jamison, P., Seitz, R., Morgenstern, N., Saito, S., . . . Gonzalez, J. (2007). Increased satisfaction with care and lower costs: Results of a randomized trial of in-home palliative care. Journal of the American Geriatric Society, 55(7), 993–1000.

Brumley, R. D., Enquidanos, S., & Cherin, D. A. (2003). Effectiveness of a home-based palliative care program for end-of-life. Journal of Palliative Medicine, 6(5), 715–724.

Callaghan, T. C., Rochat, P., Lillard, A., Claux, M.L., Odden, H., Itakura, S., . . . Singh, S. (2005). Synchrony in the onset of mental-state reasoning. Psychological Science, 16, 378–384.

Carel, J-C., Lahlou, N., Roger, M., & Chaussain, J. L. (2004). Precocious puberty and statural growth. Human Reproduction Update, 10(2), 135–147.

Carstensen, L. L. (1992). Social and emotional patterns in adulthood: Support for socioemotional selectivity. Psychology and Aging, 7(3), 331–338.

Case, R. (1985). Intellectual development: Birth to Adulthood. New York, NY: Academic.

Casey, B. J., Tottenham, N., Liston, C., & Durston, S. (2005). Imaging the developing brain: What have we learned about cognitive development? TRENDS in Cognitive Sciences, 19(3), 104–110.

Centers for Disease Control and Prevention. (2013). Smoking during pregnancy. Retrieved from http://www.cdc.gov/tobacco/basic_information/health_effects/pregnancy/

Charness, N. (1981). Search in chess: Age and skill differences. Journal of Experimental Psychology: Human Perception and Performance, 7 , 467.

Chick, K., Heilman-Houser, R., & Hunter, M. (2002). The impact of child care on gender role development and gender stereotypes. Early Childhood Education Journal, 29(3), 149–154.

Chomsky, N. (1957). Syntactic structures. The Hague, Netherlands: Mouton.

Clements, R. (2004). An investigation of the status of outdoor play. Contemporary Issues in Early Childhood, 5(1), 68–80.

Commons, M. L., & Bresette, L. M. (2006). Illuminating major creative scientific innovators with postformal stages. In C. Hoare (Ed.), Handbook of adult development and learning (pp. 255–280). New York, NY: Oxford University Press.

Connor, S. R., Pyenson, B., Fitch, K., Spence, C., & Iwasaki, K. (2007). Comparing hospice and nonhospice patient survival among patients who die within a three-year window. Journal of Pain and Symptom Management, 33(3), 238–246.

Courage, M. L., & Howe, M. L. (2002). From infant to child: The dynamics of cognitive change in the second year of life. Psychological Bulletin, 128, 250–277.

Craik, F. I., & Bialystok, E. (2006). Cognition through the lifespan: mechanisms of change.  Trends in Cognitive Sciences, 10 , 131–138.

Craik, F. I. M. (2000). Age-related changes in human memory. In D. C. Park & N. Schwarz (Eds.),  Cognitive Aging: A Primer  (pp. 75–92). New York: Psychology Press.

Curtiss, S. (1981). Dissociations between language and cognition: Cases and implications. Journal of Autism and Developmental Disorders, 11(1), 15–30.

Darling, N. (1999). Parenting style and its correlates. Retrieved from ERIC database (EDO-PS-99-3) http://ecap.crc.illinois.edu/eecearchive/digests/1999/darlin99.pdf

de Hevia, M. D., & Spelke, E. S. (2010). Number-space mapping in human infants. Psychological Science, 21(5), 653–660.

Dennett, D. (1987). The intentional stance. Cambridge, MA: MIT Press.

Diamond, A. (2009). The interplay of biology and the environment broadly defined. Developmental Psychology, 45(1), 1–8.

Donenberg, G. R., Wilson, H. W., Emerson, E., Bryant, F. B. (2002). Holding the line with a watchful eye: The impact of perceived parental permissiveness and parental monitoring on risky sexual behavior among adolescents in psychiatric care. AIDS Education Prevention, 14(2), 138–157.

Dornbusch, S. M., Ritter, P. L., Leiderman, P. H., Roberts, D. F., & Fraleigh, M. J. (1987). The relation of parenting style to adolescent school performance. Child Development, 58(5), 1244–1257.

Duncan, G. J., & Magnuson, K. A. (2005). Can family socioeconomic resources account for racial and ethnic test score gaps? The Future of Children, 15(1), 35–54.

Erikson, E. H. (1963). Childhood and Society (2nd ed.). New York, NY: Norton.

Erikson, E. H. (1968). Identity: Youth and crisis. New York, NY: Norton.

Ferrer, M., & Fugate, A. (2003). Helping your school-age child develop a healthy self-concept. Retrieved from http://edis.ifas.ufl.edu/fy570#FOOTNOTE_2

Figdor, E., & Kaeser, L. (1998). Concerns mount over punitive approaches to substance abuse among pregnant women. The Guttmacher Report on Public Policy 1(5), 3–5.

Fischer, K. W., Yan, Z., & Stewart, J. (2003). Adult cognitive development: Dynamics in the developmental web. In J. Valsiner & K Connolly (Eds.), Handbook of developmental psychology (pp. 491–516). Thousand Oaks, CA: Sage Publications.

Flannery, D. J., Rowe, D. C., & Gulley, B. L. (1993). Impact of pubertal status, timing, and age on adolescent sexual experience and delinquency. Journal of Adolescent Research, 8, 21–40.

Freud, S. (1909). Analysis of a phobia in a five-year-old boy. In Collected Papers: Volume 111, Case Histories (1949) (pp. 149–289). Hogarth Press: London.

Fromkin, V., Krashen, S., Curtiss, S., Rigler, D., & Rigler, M. (1974). The development of language in Genie: A case of language acquisition beyond the critical period. Brain and Language, 1, 81–107.

Galambos, N. L., & Almeida, D. M. (1992). Does parent-adolescent conflict increase in early adolescence? Journal of Marriage and the Family, 54, 737–747.

Ganger, J., & Brent, M.R. (2004). Reexamining the vocabulary spurt. Developmental Psychology, 40(4), 621–632.

Ge, X., Conger, R. D., & Elder, G. H. (2001). Pubertal transition, stressful life events, and the emergence of gender differences in adolescent depressive symptoms. Developmental Psychology, 37, 404–417.

Gervai, J. (2009). Environmental and genetic influences on early attachment. Child and Adolescent Psychiatry and Mental Health, 3, 25.

Gesell, A. (1933). Maturation and the patterning of behavior. In C. Murchison (Ed.), A handbook of child psychology (2nd ed., pp. 209–235). Worcester, MA: Clark University Press.

Gesell, A. (1939). Biographies of child development. New York, NY: Paul B. Hoeber.

Gesell, A. (1940). The first five years of life. New York, NY: Harper.

Gesell, A., & Ilg, F. L. (1946). The child from five to ten. New York, NY: Harper.

Gilligan, C. (1982). In a different voice: Psychological theory and women's development. Cambridge, MA: Harvard University Press.

Gleitman, L.R., & Newport, E. L. (1995). The invention of language by children: Environmental and biological influences on the acquisition of language. In D.N. Osherson , L.R. Gleitman, & M. Liberman (Eds.), An invitation to cognitive science: Language (pp. 1–24). Cambridge, MA: The MIT Press.

Gleitman, L. R., & Newport, E. L. (1995). The invention of language by children: Environmental and biological influences on the acquisition of language. In L. R. Gleitman & M. Liberman (Eds.), An invitation to cognitive science, Vol. 1: Language. (2nd ed.) (pp. 1–24). Cambridge, MA: MIT Press.

Godkin, M., Krant, M., & Doster, N. (1984). The impact of hospice care on families. International Journal of Psychiatry in Medicine, 13, 153–165.

Graber, J. A., Lewinsohn, P. M., Seeley, J. R., & Brooks-Gunn, J. (1997). Is psychopathology associated with the timing of pubertal development? Journal of the Academy of Child and Adolescent Psychiatry, 36, 1768–1776.

Hair, E. C., Moore, K. A., Garrett, S. B., Kinukawa, A., Lippman, L., & Michelson, E. (2005). The parent-adolescent relationship scale. In L. Lippman (Ed.), Conceptualizing and Measuring Indicators of Positive Development: What Do Children Need to Fluorish? (pp. 183–202). New York, NY: Kluwer Academic/Plenum Press.

Hall, S. S. (2004, May). The good egg. Discover, 30–39.

Hall, G. S. (1904). Adolescence. New York, NY: Appleton.

Harlow, H. (1958). The nature of love. American Psychologist, 13, 673–685.

Harris, J. R. (2009). The nurture assumption: Why children turn out the way they do (2nd ed.). New York, NY: Free Press.

Hart, B., & Risley, T. R. (2003). The early catastrophe: The 30 million word gap. American Educator, 27(1), 4–9.

Hasher, L. & Zacks, R. T. (1988). Working memory, comprehension, and aging: A review and a new view. In G.H. Bower (Ed.),  The Psychology of Learning and Motivation , (Vol. 22, pp. 193–225). San Diego, CA: Academic Press.

Hatch, E. (1983). Psycholinguistics: A second language perspective. Rowley, MA: Newbury House.

Hertzog, C., Kramer, A. F., Wilson, R. S., & Lindenberger, U. (2009). Enrichment effects on adult cognitive development. Psychological Science in the Public Interest, 9(1), 1–65.

Hood, R. W., Jr., Spilka, B., Hunsberger, B., & Corsuch, R. (1996). The psychology of religion: An empirical approach (2nd ed.). New York, NY: Guilford.

Huebler, F. (2005, December 14). International education statistics [Web log post]. Retrieved from http://huebler.blogspot.com/2005/12/age-and-level-of-education-in-nigeria.html

Hutchinson, N. (2011). A geographically informed vision of skills development. Geographical Education, 24, 15.

Huttenlocher, P. R., & Dabholkar, A. S. (1997). Regional differences in synaptogenesis in human cerebral cortex. Journal of Comparative Neurology, 387(2), 167–178.

Iverson, J.M., & Goldin-Meadow, S. (2005). Gesture paves the way for language development. Psychological Science, 16(5), 367–71.

Iyengar, S. S., Wells, R. E., & Schwartz, B. (2006). Doing better but feeling worse: Looking for the best job undermines satisfaction. Psychological Science, 17, 143–150.

Jos, P. H., Marshall, M. F., & Perlmutter, M. (1995). The Charleston policy on cocaine use during pregnancy: A cautionary tale. The Journal of Law, Medicine & Ethics, 23(2), 120–128.

Kaltiala-Heino, R. A., Rimpela, M., Rissanen, A., & Rantanen, P. (2001). Early puberty and early sexual activity are associated with bulimic-type eating pathology in middle adolescence. Journal of Adolescent Health, 28, 346–352.

Kaplan, H., & Dove, H. (1987). Infant development among the Aché of Eastern Paraguay. Developmental Psychology, 23, 190–198.

Karasik, L. B., Adolph, K. E., Tamis-LeMonda, C. S., & Bornstein, M. H. (2010). WEIRD Walking: Cross-cultural research on motor development. Behavioral & Brain Sciences, 33(2-3), 95–96.

Karnik, S., & Kanekar, A. (2012). Childhood obesity: A global public health crisis. International Journal of Preventive Medicine, 3(1), 1–7.

Kohlberg, L. (1969). Stage and sequence: The cognitive-developmental approach to socialization. In D. A. Goslin (Ed.), Handbook of socialization theory and research (p. 379). Chicago, IL: Rand McNally.

Kolb, B., & Whishaw, I. Q. (2009). Fundamentals of human neuropsychology. New York, NY: Worth.

Kübler-Ross, E. (1969). On death and dying. New York, NY: Macmillan.

Labouvie-Vief, G., & Diehl, M. (1999). Self and personality development. In J. C. Cavanaugh & S. K. Whitbourne (Eds.), Gerontology: An interdisciplinary perspective (pp. 238–268). New York, NY: Oxford University Press.

Larson, E. B., Wang, L., Bowen, J. D., McCormick, W. C., Teri, L., Crane, P., & Kukull, W. (2006). Exercise is associated with reduced risk for incident dementia among persons 65 years of age or older. Annals of Internal Medicine, 144, 73–81.

Lee, V. E., & Burkam, D. T. (2002). Inequality at the starting gate: Social background differences in achievement as children begin school. Washington, DC: Economic Policy Institute.

Lobo, I. (2008) Environmental influences on gene expression. Nature Education 1(1), 39.

Loop, E. (2013). Major milestones in cognitive development in early childhood. Retrieved from http://everydaylife.globalpost.com/major-milestones-cognitive-development-early-childhood-4625.html

Maccoby, E. (1980). Social development: Psychological growth and the parent-child relationship. New York, NY: Harcourt Brace Jovanovich.

MacFarlane, A. (1978, February). What a baby knows. Human Nature, 74–81.

Maier, S. E., & West, J. R. (2001). Drinking patterns and alcohol-related birth defects. Alcohol Research & Health, 25(3), 168–174.

Main, M., & Solomon, J. (1990). Procedures for identifying infants as disorganized/disoriented during the Ainsworth Strange Situation. In M. T. Greenberg, D. Cicchetti, & E. M. Cummings (Eds.), Attachment in the Preschool Years (pp. 121–160). Chicago, IL: University of Chicago Press.

Markus, H. R., Ryff, C. D., Curan, K., & Palmersheim, K. A. (2004). In their own words: Well-being at midlife among high school-educated and college-educated adults. In O. G. Brim, C. D. Ryff, & R. C. Kessler (Eds.), How healthy are we? A national study of well-being at midlife (pp. 273–319). Chicago, IL: University of Chicago Press.

McIntosh, D. N., Silver, R. C., & Wortman, C. B. (1993). Religion’s role in adjustment to a negative life event: Coping with the loss of a child. Journal of Personality and Social Psychology, 65, 812–821.

McMillan, S. C., Small, B. J., Weitzner, M., Schonwetter, R., Tittle, M., Moody, L., & Haley, W. E. (2006). Impact of coping skills intervention with family caregivers of hospice patients with cancer. Cancer, 106(1), 214-222.

Miklikowska, M., Duriez, B., & Soenens, B. (2011). Family roots of empathy-related characteristics: The role of perceived maternal and paternal need support in adolescence. Developmental Psychology, 47(5), 1342–1352.

Mills, M., & Melhuish, E. (1974). Recognition of mother’s voice in early infancy. Nature, 252, 123–124.

Mohr, R. D., & Zoghi, C. (2006). Is job enrichment really enriching? (U.S. Bureau of Labor Statistics Working Paper 389). Washington, DC: U.S. Bureau of Labor Statistics. Retrieved from http://www.bls.gov/ore/pdf/ec060010.pdf

Moore, K. A., Guzman, L., Hair, E. C., Lippman, L., & Garrett, S. B. (2004). Parent-teen relationships and interactions: Far more positive than not. Child Trends Research Brief, 2004-25. Washington, DC: Child Trends.

National Institutes of Health. (2013). What is prenatal care and why is it important? Retrieved from http://www.nichd.nih.gov/health/topics/pregnancy/conditioninfo/Pages/prenatal-care.aspx

Nolen-Hoeksema, S., & Larson, J. (1999). Coping with loss. Mahweh, NJ: Erlbaum.

Overman, W. H., Bachevalier, J., Turner, M., & Peuster, A. (1992). Object recognition versus object discrimination: Comparison between human infants and infant monkeys. Behavioral Neuroscience, 106, 15–29.

Paloutzian, R. F. (1996). Invitation to the psychology of religion. Boston, MA: Allyn & Bacon.

Parent, J., Forehand, R., Merchant, M. J., Edwards, M. C., Conners-Burrow, N. A., Long, N., & Jones, D. J. (2011). The relation of harsh and permissive discipline with child disruptive behaviors: Does child gender make a difference in an at-risk sample? Journal of Family Violence, 26, 527–533.

Park, D. C. (2000). The basic mechanisms accounting for age-related decline in cognitive function. In D.C. Park & N. Schwarz (Eds.),  Cognitive Aging: A Primer  (pp. 3–21). New York: Psychology Press.

Park, D. C. & Gutchess, A. H. (2000). Cognitive aging and everyday life. In D.C. Park & N. Schwarz (Eds.),  Cognitive Aging: A Primer  (pp. 217–232). New York: Psychology Press.

Piaget, J. (1954). The construction of reality in the child. New York: Basic Books.

Pickens, J. (1994). Full-term and preterm infants’ perception of face-voice synchrony. Infant Behavior and Development, 17, 447–455.

Piaget, J. (1930). The child’s conception of the world. New York, NY: Harcourt, Brace & World.

Piaget, J. (1932). The moral judgment of the child. New York, NY: Harcourt, Brace & World.

Podewils, L. J., Guallar, E., Kuller, L. H., Fried, L. P., Lopez, O. L., Carlson, M., & Lyketsos, C. G. (2005). Physical activity, APOE genotype, and dementia risk: Findings from the Cardiovascular Health Cognition Study. American Journal of Epidemiology, 161, 639–651.

Pollack, W., & Shuster, T. (2000). Real boys’ voices. New York, NY: Random House.

Rhodes, R. L., Mitchell, S. L., Miller, S. C., Connor, S. R., & Teno, J. M. (2008). Bereaved family members' evaluation of hospice care: What factors influence overall satisfaction with services? Journal of Pain and Symptom Management, 35, 365–371.

Risley, T. R., & Hart, B. (2006). Promoting early language development. In N. F. Watt, C. Ayoub, R. H. Bradley, J. E. Puma, & W. A. LeBoeuf (Eds.), The crisis in youth mental health: Early intervention programs and policies (Vol. 4, pp. 83–88). Westport, CT: Praeger.

Rothbaum, R., Weisz, J., Pott, M., Miyake, K., & Morelli, G. (2000). Attachment and culture: Security in the United States and Japan. American Psychologist, 55, 1093–1104.

Russell, S. T., Crockett, L. J., & Chao, R. (Eds.). (2010). Asian American parenting and parent-adolescent relationships. In R. Levesque (Series Ed.), Advancing responsible adolescent development. New York, NY: Springer.

Ryff, C. D., & Singer, B. (2009). Understanding healthy aging: Key components and their integration. In V. L. Bengtson, D. Gans., N. M. Putney, & M. Silverstein. (Eds.), Handbook of theories of aging (2nd ed., pp. 117–144). New York, NY: Springer.

Salthouse, T. A. (2004). What and when of cognitive aging.  Current Directions in Psychological Science, 13 , 140–144.

Salthouse, T. A. (1984). Effects of age and skill in typing.  Journal of Experimental Psychology: General, 113 , 345.

Samarel, N. (1991). Caring for life after death. Washington, DC: Hemisphere.

Sanson, A., & Rothbart, M. K. (1995). Child temperament and parenting. In M. Bornstein (Ed.), Applied and practical parenting (Vol. 4, pp. 299–321). Mahwah, NJ: Lawrence Erlbaum.

Schaie, K. W. & Willis, S. L. (1996). Psychometric intelligence and aging. In F. Blanchard-Fields & T.M. Hess (Eds.),  Perspectives on Cognitive Change in Adulthood and Aging  (pp. 293–322). New York: McGraw Hill.

Schechter, C., & Byeb, B. (2007). Preliminary evidence for the impact of mixed-income preschools on low-income children’s language growth. Early Childhood Research Quarterly, 22, 137–146.

Shamay-Tsoory, S. G., Tomer, R., & Aharon-Peretz, J. (2005). The neuroanatomical basis of understanding sarcasm and its relationship to social cognition. Neuropsychology, 19(3), 288–300.

Shanahan, L., McHale, S. M., Osgood, D. W., & Crouter, A. C. (2007). Conflict frequency with mothers and fathers from middle childhood to late adolescence: Within and between family comparisons. Developmental Psychology, 43, 539–550.

Siegler, R. S. (2005). Children’s thinking (4th ed). Mahwah, NJ: Erlbaum.

Siegler, R. S. (2006). Microgenetic analyses of learning. In D. Kuhn & R. S. Siegler (Eds.), Handbook of child psychology: Cognition, perception, and language (6th ed., Vol. 2). New York: Wiley.

Sinnott, J. D. (1998). The development of logic in adulthood: Postformal thought and its applications. New York, NY: Springer.

Small, M. F. (1999). Our babies, ourselves: How biology and culture shape the way we parent. New York, NY: Anchor Books.

Spelke, E.S., & Cortelyou, A. (1981). Perceptual aspects of social knowing: Looking and listening in infancy. In M.E. Lamb & L.R. Sherrod (Eds.), Infant social cognition: Empirical and theoretical considerations (pp. 61–83). Hillsdale, NJ: Erlbaum.

Steinberg, L., & Morris, A. S. (2001). Adolescent development. Annual Review of Psychology, 52, 83–110.

Sterns, H. L., & Huyck, M. H. (2001). The role of work in midlife. In M. Lachman (Ed.), The handbook of midlife development (pp. 447–486). New York, NY:Wiley.

Steven L. Youngentob, et. al. (2007). Experience-induced fetal plasticity: The effect of gestational ethanol exposure on the behavioral and neurophysiologic olfactory response to ethanol odor in early postnatal and adult rats. Behavioral Neuroscience, 121(6), 1293–1305.

Stork, F. C., & Widdowson, D. A. (1974). Learning about linguistics. London, UK: Hutchinson Ltd.

Stone, A. A., Schwartz, J. E., Broderick, J. E., & Deaton, A. (2010). A snapshot of the age distribution of psychological well-being in the United States.  Proceedings of the National Academy of Sciences, 107 , 9985–9990.

Streissguth, A. P., Bookstein, F. L., Barr, H. M., Sampson, P. D., O’Malley, K., & Young, J. K. (2004). Risk factors for adverse life outcomes in fetal alcohol syndrome and fetal alcohol effects. Developmental and Behavioral Pediatrics, 25(4), 228–238.

Striegel-Moore, R. H., & Cachelin, F. M. (1999). Body image concerns and disordered eating in adolescent girls: Risk and protective factors. In N. G. Johnson, M. C. Roberts, & J. Worell (Eds.), Beyond appearance: A new look at adolescent girls. Washington, DC: American Psychological Association

Tanner, J. M. (1978). Fetus into man: Physical growth from conception to maturity. Cambridge, MA: Harvard University Press.

Temel, J. S., Greer, J. A., Muzikansky, A., Gallagher, E. R., Admane, S., Jackson, V. A. . . . Lynch, T. J. (2010). Early palliative care for patients with metastic non-small-cell lung cancer. New England Journal of Medicine, 363, 733–742.

Tentori, K., Osherson, D., Hasher, L., & May, C. (2001). Wisdom and aging: Irrational preferences in college students but not older adults.  Cognition, 81 , B87–B96.

Thomas, A. (1984). Temperament research: Where we are, where we are going. Merrill-Palmer Quarterly, 30(2), 103–109.

Tran, T. D., & Kelly, S. J. (2003). Critical periods for ethanol-induced cell loss in the hippocampal formation. Neurotoxicology and Teratology, 25(5), 519–528.

Umberson, D., Pudrovska, T., & Reczek, C. (2010). Parenthood, childlessness, and well-being: A life course perspective. Journal of Marriage and the Family, 72(3), 612–629.

United Nations Educational, Scientific and Cultural Organization. (2013, June). UIS Fact Sheet: Schooling for millions of children jeopardized by reductions in aid. Montreal, Canada: UNESCO Institute for Statistics.

Vaillant, G. E. (2002). Aging well. New York, NY: Little Brown & Co.

Van der Graaff, J., Branje, S., De Wied, M., Hawk, S., Van Lier, P., & Meeus, W. (2013). Perspective taking and empathetic concern in adolescence: Gender differences in developmental changes. Developmental Psychology, 50(3), 881.

van Ijzendoorn, M. H., & Sagi-Schwartz, A. (2008). Cross-cultural patterns of attachment: Universal and contextual dimensions. In J. Cassidy & P. R. Shaver (Eds.), Handbook of attachment. New York, NY: Guilford.

Vouloumanos, A., & Werker, J. F. (2004). Tuned to the signal: The privileged status of speech for young infants. Developmental Science, 7, 270–276.

WHO Multicentre Growth Reference Study Group. (2006). WHO Child growth standards: Methods and development: Length/height-for-age, weight-for-age, weight-for-length, weight-for-height and body mass index-for-age. Geneva, Switzerland: World Health Organization.

Winerman, L. (2011). Closing the achievement gap. Monitor of Psychology, 42(8), 36.

Wortman, J. H., & Park, C. L. (2008). Religion and spirituality in adjustment following bereavement: An integrative review. Death Studies

CC licensed content, Original

• Lifespan Development.  Authored by : Karenna Malavanti  Provided by: PressBooks . License : CC BY-SA-NC: Attribution-ShareAlike-NonCommercial

CC licensed content, Shared previously

• Why It Matters: Introduction to Lifespan Development. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY: Attribution Located at :  https://pressbooks.online.ucf.edu/lumenpsychology/chapter/introduction-8/
• Introduction to Theories of Development. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY-SA: Attribution-ShareAlike Located at : https://pressbooks.online.ucf.edu/lumenpsychology/chapter/outcome-theories-of-development/
• Lifespan Development Theories. Authored by : OpenStax College. License : CC BY: Attribution . License Terms : Download for free at https://openstax.org/books/psychology-2e/pages/1-introduction   Located at : https://openstax.org/books/psychology-2e/pages/9-introduction .
• Picture of happy boys. Authored by : Mahmud Rassel. Provided by : Flickr. License : CC BY-SA: Attribution-ShareAlike .  Located at : https://www.flickr.com/photos/rasselbd/6782624795 .
• What is Lifespan Development?. Authored by : OpenStax College. License : CC BY: Attribution . License Terms : Download for free at https://openstax.org/books/psychology-2e/pages/1-introduction .  Located at : https://openstax.org/books/psychology-2e/pages/9-1-what-is-lifespan-development .
• Lifespan Theories. Authored by : OpenStax College. License : CC BY: Attribution . License Terms : Download for free at https://openstax.org/books/psychology-2e/pages/1-introduction .  Located at : https://openstax.org/books/psychology-2e/pages/9-2-lifespan-theories .
• Cognitive Development. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY: Attribution Located at :  https://pressbooks.online.ucf.edu/lumenpsychology/chapter/lifespan-theories-cognitive-development/
• Psychology. Authored by : OpenStax College.  License Terms : Download for free at https://openstax.org/books/psychology-2e/pages/1-introduction .  Located at : https://openstax.org/books/psychology-2e/pages/9-2-lifespan-theories . License : CC BY: Attribution .
• Introduction to Stages of Development in Childhood. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY: Attribution Located at :  https://pressbooks.online.ucf.edu/lumenpsychology/chapter/outcome-stages-of-development/
• Stages of Development. Authored by : OpenStax College. License : CC BY: Attribution . License Terms : Download for free at https://openstax.org/books/psychology-2e/pages/1-introduction .  Located at : https://openstax.org/books/psychology-2e/pages/9-3-stages-of-development .
• Prenatal Development. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY: Attribution Located at :  https://pressbooks.online.ucf.edu/lumenpsychology/chapter/stages-of-development/
• Childhood: Physical and Cognitive Development. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY: Attribution Located at :  https://pressbooks.online.ucf.edu/lumenpsychology/chapter/reading-childhood/
• Childhood: Emotional and Social Development. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY: Attribution Located at : https://pressbooks.online.ucf.edu/lumenpsychology/chapter/childhood-emotional-and-social-development/
• Introduction to Development in Adolescence and Adulthood. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY-SA: Attribution-ShareAlike Located at :  https://pressbooks.online.ucf.edu/lumenpsychology/chapter/outcome-development-in-adolescence-and-adulthood/
• Socioemotional Development in Late Adulthood. Provided by : Boundless. License : CC BY-SA: Attribution-ShareAlike .  Located at : https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/human-development-14/aging-late-adulthood-412/socioemotional-development-in-late-adulthood-292-12827/ .
• Adolescence. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY-SA-NC: Attribution-ShareAlike-NonCommercial Located at :  https://pressbooks.online.ucf.edu/lumenpsychology/chapter/reading-adolescence/
• Brain Changes and Cognitive Development in Adolescence. Provided by : Open Learning Initiative. License : CC BY-NC-SA: Attribution-NonCommercial-ShareAlike .  Located at : https://oli.cmu.edu/jcourse/workbook/activity/page?context=df3e73250a0001dc08caae28aa5ca73a .
• Adulthood. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY-SA-NC: Attribution-ShareAlike-NonCommericial Located at :  https://pressbooks.online.ucf.edu/lumenpsychology/chapter/reading-adulthood/
• Signs of Aging interactive. Authored by : Jessica Traylor for Lumen Learning. Provided by : Lumen Learning. License :  CC BY: Attribution
• Section on cognitive development. Authored by : Tara Queen and Jacqui Smith . Provided by : University of Michigan. Project : The Noba Project.   License : CC BY-NC-SA: Attribution-NonCommercial-ShareAlike .  Located at : http://nobaproject.com/modules/aging .
• Physical Development in Late Adulthood. Provided by : Boundless. License : CC BY: Attribution .  Located at : https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/human-development-14/aging-late-adulthood-412/physical-development-in-late-adulthood-291-12826/ .
• Putting It Together: Lifespan Development. Authored by :  Lumen Learning Provided by : Lumen Learning. License : CC BY-SA-NC: Attribution-ShareAlike-NonCommercial Located at :  https://pressbooks.online.ucf.edu/lumenpsychology/chapter/putting-it-together-lifespan-development/
• Section on Adolescent Development. Authored by : Jennifer Lansford . Provided by : Duke University. Project : The Noba Project. License : CC BY-NC-SA: Attribution-NonCommercial-ShareAlike .  Located at : http://nobaproject.com/modules/adolescent-development?r=MTc0ODYsMzIxMDM%3D .

All Rights Reserved Content

• Piaget - Stage 1 - Sensorimotor stage : Object Permanence. Authored by : Geert Stienissen. License : Other. License Terms : Standard YouTube License .  Located at : https://www.youtube.com/watch?v=NCdLNuP7OA8 .
• A typical child on Piaget's conservation tasks. Authored by : munakatay. License : Other. License Terms : Standard YouTube License .  Located at : https://www.youtube.com/watch?v=gnArvcWaH6I .
• Piaget's Mountains Task. Authored by : UofMNCYFC. License : Other. License Terms : Standard YouTube License .  Located at : https://www.youtube.com/watch?v=v4oYOjVDgo0 .
• The False Belief Test: Theory of Mind. Authored by : 007IceWeasel. License : Other. License Terms : Standard YouTube License .  Located at : https://www.youtube.com/watch?v=8hLubgpY2_w .
• The Strange Situation - Mary Ainsworth. Authored by : thibs44. License : Other. License Terms : Standard YouTube License .  Located at : https://www.youtube.com/watch?v=QTsewNrHUHU .
• How to Be the Oldest Person Alive. Authored by : Glamour Magazine. License : Other. License Terms : Standard YouTube License .  Located at : https://www.youtube.com/watch?v=I62njq9gsaI .

study of development using norms, or average ages, when most children reach specific developmental milestones

all of the beliefs, customs, art, and traditions of a particular society

view that development is a cumulative process: gradually improving on existing skills

view that development takes place in unique stages, which happen at specific times or ages

process proposed by Freud in which pleasure-seeking urges focus on different erogenous zones of the body as humans move through five stages of life

domain of lifespan development that examines emotions, personality, and social relationships from infancy through adulthood, proposed by Erikson

(plural = schemata) mental construct consisting of a cluster or collection of related concepts

adjustment of a schema by adding information similar to what is already known

adjustment of a schema by changing a scheme to accommodate new information different from what was already known

idea that even if something is out of sight, it still exists

second stage in Piaget’s theory of cognitive development; from ages 2 to 7, children learn to use symbols and language but do not understand mental operations and often think illogically

idea that even if you change the appearance of something, it is still equal in size, volume, or number as long as nothing is added or removed

preoperational child’s difficulty in taking the perspective of others

third stage in Piaget’s theory of cognitive development; from about 7 to 11 years old, children can think logically about real (concrete) events

principle that objects can be changed, but then returned back to their original form or condition

structure created when a sperm and egg merge at conception; begins as a single cell and rapidly divides to form the embryo and placenta

multi-cellular organism in its early stages of development

structure connected to the uterus that provides nourishment and oxygen to the developing baby

medical care during pregnancy that monitors the health of both the mother and the fetus

time during fetal growth when specific parts or organs develop

inborn automatic response to a particular form of stimulation that all healthy babies are born with

ability to move our body and manipulate objects

use of muscles in fingers, toes, and eyes to coordinate small actions

use of large muscle groups to control arms and legs for large body movements

long-standing connection or bond with others

parental presence that gives the infant/toddler a sense of safety as they explore their surroundings

characterized by the child using the parent as a secure base from which to explore

characterized by child’s unresponsiveness to parent, does not use the parent as a secure base, and does not care if parent leaves

characterized by the child’s tendency to show clingy behavior and rejection of the parent when they attempt to interact with the child

characterized by the child’s odd behavior when faced with the parent; type of attachment seen most often with kids that are abused

parents give children reasonable demands and consistent limits, express warmth and affection, and listen to the child’s point of view

parents place a high value on conformity and obedience, are often rigid, and express little warmth to the child

parents make few demands and rarely use punishment

parents are indifferent, uninvolved, and sometimes referred to as neglectful; they don’t respond to the child’s needs and make relatively few demands

period of development that begins at puberty and ends at early adulthood

newly defined period of lifespan development from 18 years old to the mid-20s; young people are taking longer to complete college, get a job, get married, and start a family

information processing abilities, such as logical reasoning, remembering lists, spatial ability, and reaction time

intelligence that draw upon experience and knowledge. Measures include vocabulary tests, solving number problems, and understanding texts

Psychological Science: Understanding Human Behavior Copyright © by Karenna Malavanti is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted.

Share This Book

• Biology Article

Human Life Cycle

Introduction.

Human beings are culture species that fall under the genus Homo and the family Hominidae. In appearance, human beings are physically similar to apes. Earlier, only human beings were the species exclusive to the family Hominidae. But a recent study suggests that chimpanzees are more closely related to humans than gorillas and the last mutual ancestor between humans and chimpanzees, lived about 6 to 7 million years ago.

A human body consists of four limbs; which are two arms and legs, and a head and neck attached to the torso. The shape of the human body is formed from a strong skeleton which is made of bone and cartilage, covered with fat, muscle, organs, tissue and so on.

A huge difference between apes and humans is that humans have a more developed or evolved brain. The body structure of human beings is erect and showcases movable hands. Apes also show great cognitive talent which was earlier unknown to humans.

The human body undergoes numerous changes and developments since conception. The food humans eat, helps them to develop. If we look at this historical trail of human evolution, there are many highlights to be looked upon. But for now, let’s look at the life cycle of a human being to get a better understanding.

Life Cycle of Human

The following are the different stages of development in the human life cycle

The sperm from the adult male human and the egg from the adult female human form a zygote inside the uterus of the female. Over time, the zygote develops and forms an embryo. Initially, the embryo looks like a cluster of cells, but after eight weeks, the embryo resembles the human body and is called a foetus. During this stage, the foetus is entirely dependent on the female for breathing, eating and other kinds of resources.

2) Infancy:

After around nine months, the foetus is fully developed to be born. This stage in human development marks the period from birth to age one. Infancy is the earliest part of childhood, where the infant grows in size and shape. During this stage, infant requires a lot of attention as they are completely dependent on their mothers. Infants develop their behaviour, physiology and cognition. Gradually, the infants learn to suck, swallow and cry if they are in an uncomfortable situation. Since infants are unable to speak, crying is their way of communicating. The mother tends to breastfeed her infant during this stage.

3) Toddler years:

The term ‘to toddle’ means to walk unsteadily and the child has a clumsy walk during this period. This stage marks the end of early childhood. During this period, the child ages two to three years old. This stage in a child’s life is where they undergo immense cognitive, emotional and social development.

4) Childhood:

Here, a child is of age three to six years and is crawling for mobility. In this stage, the child crawls and eventually learns to walk, talk, eat independently, and become more aware of their surroundings. The child is more social and active during this period and intrigued to learn new things.

5) Adolescence:

Here, the child is of age from nine to thirteen years and this period marks the beginning of adolescence. In this stage, the child grows into an adolescent, through a period called puberty. Puberty occurs during the initial stages of their teenage years, and that’s why adolescents are also called teenagers. In this stage, the teenager grows rapidly and physical changes begin to appear. These changes include hair growth, structural changes in body shape, voice cracking in adolescent males, breast growth in adolescent females and so on.

The behaviour pattern also changes, as they are more independent in performing daily tasks.

6) Adulthood:

Human beings who are between the age of 20 to 60 years are known as adults. Here, human beings are sexually mature and capable of reproducing. The body is fully developed by now, and the adult gains experience and responsibility. Adults have full mental and social development by this stage.

7) Middle age:

This is the time period of adulthood between the age of 30 to 50 years.

8) Old age:

When an individual reaches 60 or 65 years of age, they are called old people. This period starts from 65 years of age, until the end of their lives. During this stage, the intestine absorbs fewer nutrients from food sources. The physical capabilities of doing tasks are also reduced and they again depend on external support to do things.

The behaviour of old people in this stage varies, depending on the immunity and lifestyle of the human. The average life expectancy of human beings varies from 70 to 85 years. But this also changes depending on their lifestyle.

A human being’s body undergoes several changes and developments throughout their life span and food acts as the fuel needed for all these changes. Proper nutrition, exercise and a friendly environment ensure a healthy human beings in all stages of their life. Some basic nutrients required for human growth are carbohydrates, essential amino acids, fatty acids, vitamins and minerals in order to sustain a healthy lifestyle.

Frequently Asked Questions on Life Cycle of Human

What are the six stages of the human life cycle.

The six stages of human development include the foetus, infancy, toddler years, childhood, puberty, adolescence, adulthood, middle age and senior years.

What are the characteristics of human development?

The growth of different characteristics that occur is body structure, aptitude, intelligence, height, weight, hair colour, and sexual orientation.

What are the main objectives of human development?

The main objectives of human development include health, education, physical development and freedom. The objectives should also include human rights and social, economical and political freedom.

To explore more information on human beings and other species, register with BYJU’S Biology .

Put your understanding of this concept to test by answering a few MCQs. Click ‘Start Quiz’ to begin!

Select the correct answer and click on the “Finish” button Check your score and answers at the end of the quiz

Visit BYJU’S for all Biology related queries and study materials

Your result is as below

Request OTP on Voice Call

Leave a Comment Cancel reply

Your Mobile number and Email id will not be published. Required fields are marked *

Post My Comment

• Share Share

Register with BYJU'S & Download Free PDFs

Register with byju's & watch live videos.

Home — Essay Samples — Philosophy — Carl Jung — Carl Jung And Stages Of Life

Carl Jung and Stages of Life

• Categories: Carl Jung

About this sample

Words: 716 |

Published: Aug 6, 2021

Words: 716 | Pages: 2 | 4 min read

Table of contents

Introduction, the athlete, the warrior, the statement.

Cite this Essay

Let us write you an essay from scratch

• 450+ experts on 30 subjects ready to help
• Custom essay delivered in as few as 3 hours

Get high-quality help

Dr. Heisenberg

Verified writer

• Expert in: Philosophy

+ 120 experts online

By clicking “Check Writers’ Offers”, you agree to our terms of service and privacy policy . We’ll occasionally send you promo and account related email

No need to pay just yet!

Related Essays

3.5 pages / 1522 words

2.5 pages / 1195 words

1.5 pages / 717 words

3.5 pages / 1549 words

Remember! This is just a sample.

You can get your custom paper by one of our expert writers.

121 writers online

Still can’t find what you need?

Browse our vast selection of original essay samples, each expertly formatted and styled

Related Essays on Carl Jung

Carl Jung, a Swiss psychiatrist and psychoanalyst, is renowned for his contributions to the field of psychology, particularly his influential theories on human nature. Jung's perspective on human nature is multifaceted, [...]

Two of the many major contributors to humanistic psychology are Carl Jung and Rollo May. Carl Jung is definitely one of the most important, yet controversial, figures in psychology. Many see him as more than just a historical [...]

Sigmund Freud and Carl Jung both author two separate Psychodynamic Theories of Personality. While former colleagues and even close friends at one time, differences related to their studies led to a falling out. After Jung and [...]

The literary critics Alexander Pope and Immanuel Kant put critics to the test as they perform the task of critiquing critiques. In Pope’s Essay on Criticism, he provides the readers and critics with critique of critics in [...]

In the 17th century, political philosophy was widely practised as a discipline adhering to the psychological-realist school. Whereby, theories of governance and the state were theorised based on what humans are, not as what the [...]

The phenomenon of morality and its origination has been a topic of debate throughout history. Specifically, the world renowned philosophers, David Hume and Immanuel Kant, come to a very significant disagreement over the history [...]

Related Topics

By clicking “Send”, you agree to our Terms of service and Privacy statement . We will occasionally send you account related emails.

Where do you want us to send this sample?

By clicking “Continue”, you agree to our terms of service and privacy policy.

Be careful. This essay is not unique

This essay was donated by a student and is likely to have been used and submitted before

Download this Sample

Free samples may contain mistakes and not unique parts

Sorry, we could not paraphrase this essay. Our professional writers can rewrite it and get you a unique paper.

Please check your inbox.

We can write you a custom essay that will follow your exact instructions and meet the deadlines. Let's fix your grades together!

Get Your Personalized Essay in 3 Hours or Less!

We use cookies to personalyze your web-site experience. By continuing we’ll assume you board with our cookie policy .

• Instructions Followed To The Letter
• Deadlines Met At Every Stage
• Unique And Plagiarism Free

29 Stages of Human Development

Learning Objectives

By the end of this section, you will be able to:

• Describe the stages of prenatal development and recognize the importance of prenatal care
• Discuss physical, cognitive, and emotional development that occurs from infancy through childhood
• Discuss physical, cognitive, and emotional development that occurs during adolescence
• Discuss physical, cognitive, and emotional development that occurs in adulthood

From the moment we are born until the moment we die, we continue to develop.

As discussed at the beginning of this chapter, developmental psychologists often divide our development into three areas: physical development, cognitive development, and psychosocial development. Mirroring Erikson’s stages, lifespan development is divided into different stages that are based on age. We will discuss prenatal, infant, child, adolescent, and adult development.

Prenatal Development

How did you come to be who you are? From beginning as a one-cell structure to your birth, your prenatal development occurred in an orderly and delicate sequence.

There are three stages of prenatal development: germinal, embryonic, and fetal. Let’s take a look at what happens to the developing baby in each of these stages.

Germinal Stage (Weeks 1–2)

In the discussion of biopsychology earlier in the book, you learned about genetics and DNA. A mother and father’s DNA is passed on to the child at the moment of conception. Conception occurs when sperm fertilizes an egg and forms a zygote . A zygote begins as a one-cell structure that is created when a sperm and egg merge . The genetic makeup and sex of the baby are set at this point. During the first week after conception, the zygote divides and multiplies, going from a one-cell structure to two cells, then four cells, then eight cells, and so on. This process of cell division is called mitosis . Mitosis is a fragile process, and fewer than one-half of all zygotes survive beyond the first two weeks (Hall, 2004). After five days of mitosis there are one hundred cells, and after nine months there are billions of cells. As the cells divide, they become more specialized, forming different organs and body parts. In the germinal stage , the mass of cells has yet to attach itself to the lining of the mother’s uterus . Once it does, the next stage begins.

Embryonic Stage (Weeks 3–8)

After the zygote divides for about 7–10 days and has 150 cells, it travels down the fallopian tubes and implants itself in the lining of the uterus. Upon implantation, this multi-cellular organism is called an embryo . Now blood vessels grow, forming the placenta. The placenta is a structure connected to the uterus that provides nourishment and oxygen from the mother to the developing embryo via the umbilical cord . Basic structures of the embryo start to develop into areas that will become the head, chest, and abdomen. During the embryonic stage , the heart begins to beat and organs form and begin to function . The neural tube forms along the back of the embryo, developing into the spinal cord and brain.

Fetal Stage (Weeks 9–40)

When the organism is about 9 weeks old , the embryo is called a fetus . At this stage, the fetus is about the size of a kidney bean and begins to take on the recognizable form of a human being as the “tail” begins to disappear.

From 9–12 weeks, the sex organs begin to differentiate. At about 16 weeks, the fetus is approximately 4.5 inches long. Fingers and toes are fully developed, and fingerprints are visible. By the time the fetus reaches the sixth month of development (24 weeks), it weighs up to 1.4 pounds. Hearing has developed, so the fetus can respond to sounds. The internal organs, such as the lungs, heart, stomach, and intestines, have formed enough that a fetus born prematurely at this point has a chance to survive outside of the mother’s womb. Throughout the fetal stage the brain continues to grow and develop, nearly doubling in size from weeks 16 to 28. Around 36 weeks, the fetus is almost ready for birth. It weighs about 6 pounds and is about 18.5 inches long, and by week 37 all of the fetus’s organ systems are developed enough that it could survive outside the mother’s uterus without many of the risks associated with premature birth. The fetus continues to gain weight and grow in length until approximately 40 weeks. By then, the fetus has very little room to move around and birth becomes imminent.

Prenatal Influences

During each prenatal stage, genetic and environmental factors can affect development. The developing fetus is completely dependent on the mother for life. It is important that the mother takes good care of herself and receives prenatal care , which is medical care during pregnancy that monitors the health of both the mother and the fetus. According to the National Institutes of Health ([NIH], 2013), routine prenatal care is important because it can reduce the risk of complications for the mother and fetus during pregnancy. In fact, women who are trying to become pregnant or who may become pregnant should discuss pregnancy planning with their doctor. They may be advised, for example, to take a vitamin containing folic acid, which helps prevent certain birth defects, or to monitor aspects of their diet or exercise routines.

Recall that when the zygote attaches to the wall of the mother’s uterus, the placenta is formed. The placenta provides nourishment and oxygen to the fetus. Most everything the mother ingests, including food, liquid, and even medication, travels through the placenta to the fetus, hence the common phrase “eating for two.” Anything the mother is exposed to in the environment affects the fetus; if the mother is exposed to something harmful, the child can show life-long effects.

A teratogen is any environmental agent—biological, chemical, or physical—that causes damage to the developing embryo or fetus . There are different types of teratogens. Alcohol and most drugs cross the placenta and affect the fetus. Alcohol is not safe to drink in any amount during pregnancy. Alcohol use during pregnancy has been found to be the leading preventable cause of intellectual disabilities in children in the United States (Maier & West, 2001). Excessive maternal drinking while pregnant can cause fetal alcohol spectrum disorders with life-long consequences for the child ranging in severity from minor to major. Fetal alcohol spectrum disorders (FASD) are a collection of birth defects associated with heavy consumption of alcohol during pregnancy. Physically, children with FASD may have a small head size and abnormal facial features. Cognitively, these children may have poor judgment, poor impulse control, higher rates of ADHD, learning issues, and lower IQ scores. These developmental problems and delays persist into adulthood (Streissguth et al., 2004). Based on studies conducted on animals, it also has been suggested that a mother’s alcohol consumption during pregnancy may predispose her child to like alcohol (Youngentob et al., 2007).

Smoking is also considered a teratogen because nicotine travels through the placenta to the fetus. When the mother smokes, the developing baby experiences a reduction in blood oxygen levels. According to the Centers for Disease Control and Prevention (2013), smoking while pregnant can result in premature birth, low-birth-weight infants, stillbirth, and sudden infant death syndrome (SIDS).

Heroin, cocaine, methamphetamine, almost all prescription medicines, and most over-the-counter medications are also considered teratogens. Babies born with a heroin addiction need heroin just like an adult addict. The child will need to be gradually weaned from the heroin under medical supervision; otherwise, the child could have seizures and die. Other teratogens include radiation, viruses such as HIV and herpes, and rubella (German measles). Women in the United States are much less likely to be afflicted with rubella because most women receive childhood immunizations or vaccinations that protect the body from disease.

Each organ of the fetus develops during a specific period in the pregnancy, called the critical or sensitive period . For example, research with primate models of FASD has demonstrated that the time during which a developing fetus is exposed to alcohol can dramatically affect the appearance of facial characteristics associated with fetal alcohol syndrome. Specifically, this research suggests that alcohol exposure that is limited to day 19 or 20 of gestation can lead to significant facial abnormalities in the offspring (Ashley, Magnuson, Omnell, & Clarren, 1999). Given regions of the brain also show sensitive periods during which they are most susceptible to the teratogenic effects of alcohol (Tran & Kelly, 2003).

Should Women Who Use Drugs During Pregnancy Be Arrested and Jailed?

As you now know, women who use drugs or alcohol during pregnancy can cause serious lifelong harm to their children. Some people have advocated mandatory screenings for women who are pregnant and have a history of drug abuse, and if the women continue using, to arrest, prosecute, and incarcerate them (Figdor & Kaeser, 1998). This policy was tried in Charleston, South Carolina, as recently as 20 years ago. The policy was called the Interagency Policy on Management of Substance Abuse During Pregnancy and had disastrous results.

The Interagency Policy applied to patients attending the obstetrics clinic at MUSC, which primarily serves patients who are indigent or on Medicaid. It did not apply to private obstetrical patients. The policy required patient education about the harmful effects of substance abuse during pregnancy. . . . [A] statement also warned patients that protection of unborn and newborn children from the harms of illegal drug abuse could involve the Charleston police, the Solicitor of the Ninth Judicial Court, and the Protective Services Division of the Department of Social Services (DSS). (Jos, Marshall, & Perlmutter, 1995, pp. 120–121)

This policy seemed to deter women from seeking prenatal care, deterred them from seeking other social services, and was applied solely to low-income women, resulting in lawsuits. The program was canceled after 5 years, during which 42 women were arrested. A federal agency later determined that the program involved human experimentation without the approval and oversight of an institutional review board (IRB). What were the flaws in the program and how would you correct them? What are the ethical implications of charging pregnant women with child abuse?

Test Your Understanding

Infancy through childhood.

The average newborn weighs approximately 7.5 pounds. Although small, a newborn is not completely helpless because his reflexes and sensory capacities help him interact with the environment from the moment of birth. All healthy babies are born with newborn reflexes : inborn automatic responses to particular forms of stimulation. Reflexes help the newborn survive until it is capable of more complex behaviors—these reflexes are crucial to survival. They are present in babies whose brains are developing normally and usually disappear around 4–5 months old. Let’s take a look at some of these newborn reflexes. The rooting reflex is the newborn’s response to anything that touches her cheek: When you stroke a baby’s cheek, she naturally turns her head in that direction and begins to suck. The sucking reflex is the automatic, unlearned sucking motions that infants do with their mouths. Several other interesting newborn reflexes can be observed. For instance, if you put your finger into a newborn’s hand, you will witness the grasping reflex, in which a baby automatically grasps anything that touches his palms. The Moro reflex is the newborn’s response when she feels like she is falling. The baby spreads her arms, pulls them back in, and then (usually) cries. How do you think these reflexes promote survival in the first months of life?

Take a few minutes to view this brief video clip illustrating several newborn reflexes: Reflexes in newborn babies .

What can young infants see, hear, and smell? Newborn infants’ sensory abilities are significant, but their senses are not yet fully developed. Many of a newborn’s innate preferences facilitate interaction with caregivers and other humans. Although vision is their least developed sense, newborns already show a preference for faces. Babies who are just a few days old also prefer human voices, they will listen to voices longer than sounds that do not involve speech (Vouloumanos & Werker, 2004), and they seem to prefer their mother’s voice over a stranger’s voice (Mills & Melhuish, 1974). In an interesting experiment, 3-week-old babies were given pacifiers that played a recording of the infant’s mother’s voice and of a stranger’s voice. When the infants heard their mother’s voice, they sucked more strongly at the pacifier (Mills & Melhuish, 1974). Newborns also have a strong sense of smell. For instance, newborn babies can distinguish the smell of their own mother from that of others. In a study by MacFarlane (1978), 1-week-old babies who were being breastfed were placed between two gauze pads. One gauze pad was from the bra of a nursing mother who was a stranger, and the other gauze pad was from the bra of the infant’s own mother. More than two-thirds of the week-old babies turned toward the gauze pad with their mother’s scent.

Physical Development

In infancy, toddlerhood, and early childhood, the body’s physical development is rapid. On average, newborns weigh between 5 and 10 pounds, and a newborn’s weight typically doubles in 6 months and triples in 1 year. By 2 years old the weight will have quadrupled, so we can expect that a 2-year-old should weigh between 20 and 40 pounds. The average length of a newborn is 19.5 inches, increasing to 29.5 inches by 12 months and 34.4 inches by 2 years old (WHO Multicentre Growth Reference Study Group, 2006).

During infancy and childhood, growth does not occur at a steady rate (Carel, Lahlou, Roger, & Chaussain, 2004). Growth slows between 4 and 6 years old: During this time children gain 5–7 pounds and grow about 2–3 inches per year. Once girls reach 8–9 years old, their growth rate outpaces that of boys due to a pubertal growth spurt. This growth spurt continues until around 12 years old, coinciding with the start of the menstrual cycle. By 10 years old, the average girl weighs 88 pounds, and the average boy weighs 85 pounds.

We are born with all of the brain cells that we will ever have—about 100–200 billion neurons (nerve cells) whose function is to store and transmit information (Huttenlocher & Dabholkar, 1997). However, the nervous system continues to grow and develop. Each neural pathway forms thousands of new connections during infancy and toddlerhood. This period of rapid neural growth is called blooming . Neural pathways continue to develop through puberty. The blooming period of neural growth is then followed by a period of pruning, where neural connections are reduced. It is thought that pruning causes the brain to function more efficiently, allowing for mastery of more complex skills (Hutchinson, 2011). Blooming occurs during the first few years of life, and pruning continues through childhood and into adolescence in various areas of the brain.

The size of our brains increases rapidly. For example, the brain of a 2-year-old is 55% of its adult size, and by 6 years old the brain is about 90% of its adult size (Tanner, 1978). During early childhood (ages 3–6), the frontal lobes grow rapidly. Recalling our discussion of the 4 lobes of the brain earlier in this book, the frontal lobes are associated with planning, reasoning, memory, and impulse control. Therefore, by the time children reach school age, they are developmentally capable of controlling their attention and behavior. Through the elementary school years, the frontal, temporal, occipital, and parietal lobes all grow in size. The brain growth spurts experienced in childhood tend to follow Piaget’s sequence of cognitive development so that significant changes in neural functioning account for cognitive advances (Kolb & Whishaw, 2009; Overman, Bachevalier, Turner, & Peuster, 1992).

Motor development occurs in an orderly sequence as infants move from reflexive reactions (e.g., sucking and rooting) to more advanced motor functioning. For instance, babies first learn to hold their heads up, then to sit with assistance, and then to sit unassisted, followed later by crawling and then walking.

Motor skills refer to our ability to move our bodies and manipulate objects . Fine motor skills focus on the muscles in our fingers, toes, and eyes, and enable coordination of small actions (e.g., grasping a toy, writing with a pencil, and using a spoon) . Gross motor skills focus on large muscle groups that control our arms and legs and involve larger movements (e.g., balancing, running, and jumping) .

As motor skills develop, there are certain developmental milestones that young children should achieve. For each milestone there is an average age, as well as a range of ages in which the milestone should be reached. An example of a developmental milestone is sitting. On average, most babies sit alone at 7 months old. Sitting involves both coordination and muscle strength, and 90% of babies achieve this milestone between 5 and 9 months old. In another example, babies on average are able to hold up their head at 6 weeks old, and 90% of babies achieve this between 3 weeks and 4 months old. If a baby is not holding up his head by 4 months old, he is showing a delay. If the child is displaying delays on several milestones, that is reason for concern, and the parent or caregiver should discuss this with the child’s pediatrician. Some developmental delays can be identified and addressed through early intervention.

Cognitive Development

In addition to rapid physical growth, young children also exhibit significant development of their cognitive abilities. Piaget thought that children’s ability to understand objects—such as learning that a rattle makes a noise when shaken—was a cognitive skill that develops slowly as a child matures and interacts with the environment. Today, developmental psychologists think Piaget was incorrect. Researchers have found that even very young children understand objects and how they work long before they have experience with those objects (Baillargeon, 1987; Baillargeon, Li, Gertner, & Wu, 2011). For example, children as young as 3 months old demonstrated knowledge of the properties of objects that they had only viewed and did not have prior experience with them. In one study, 3-month-old infants were shown a truck rolling down a track and behind a screen. The box, which appeared solid but was actually hollow, was placed next to the track. The truck rolled past the box as would be expected. Then the box was placed on the track to block the path of the truck. When the truck was rolled down the track this time, it continued unimpeded. The infants spent significantly more time looking at this impossible event. Baillargeon (1987) concluded that they knew solid objects could not pass through each other. Baillargeon’s findings suggest that very young children have an understanding of objects and how they work, which Piaget (1954) would have said is beyond their cognitive abilities due to their limited experiences in the world.

Just as there are physical milestones that we expect children to reach, there are also cognitive milestones. It is helpful to be aware of these milestones as children gain new abilities to think, problem-solve, and communicate. For example, infants shake their head “no” around 6–9 months, and they respond to verbal requests to do things like “wave bye-bye” or “blow a kiss” around 9–12 months. Remember Piaget’s ideas about object permanence? We can expect children to grasp the concept that objects continue to exist even when they are not in sight by around 8 months old. Because toddlers (i.e., 12–24 months old) have mastered object permanence, they enjoy games like hide and seek, and they realize that when someone leaves the room they will come back (Loop, 2013). Toddlers also point to pictures in books and look in appropriate places when you ask them to find objects.

Preschool-age children (i.e., 3–5 years old) also make steady progress in cognitive development. Not only can they count, name colors, and tell you their name and age, but they can also make some decisions on their own, such as choosing an outfit to wear. Preschool-age children understand basic time concepts and sequencing (e.g., before and after), and they can predict what will happen next in a story. They also begin to enjoy the use of humor in stories. Because they can think symbolically, they enjoy pretend play and inventing elaborate characters and scenarios. One of the most common examples of their cognitive growth is their blossoming curiosity. Preschool-age children love to ask “Why?”

An important cognitive change occurs in children this age. Recall that Piaget described 2-to-3-year-olds as egocentric, meaning that they do not have an awareness of others’ points of view. Between 3 and 5 years old, children come to understand that people have thoughts, feelings, and beliefs that are different from their own. This is known as theory-of-mind (TOM). Children can use this skill to tease others, persuade their parents to purchase a candy bar, or understand why a sibling might be angry. When children develop TOM, they can recognize that others have false beliefs (Dennett, 1987; Callaghan et al., 2005).

False-belief tasks are useful in determining a child’s acquisition of theory-of-mind (TOM). Take a look at this video clip showing a false-belief task involving a box of crayons: The “False Belief” Test: Theory of Mind .

Cognitive skills continue to expand in middle and late childhood (6–11 years old). Thought processes become more logical and organized when dealing with concrete information. Children at this age understand concepts such as the past, present, and future, giving them the ability to plan and work toward goals. Additionally, they can process complex ideas such as addition and subtraction and cause-and-effect relationships. However, children’s attention spans tend to be very limited until they are around 11 years old. After that point, it begins to improve through adulthood.

One well-researched aspect of cognitive development is language acquisition. As mentioned earlier, the order in which children learn language structures is consistent across children and cultures (Hatch, 1983). You’ve also learned that some psychological researchers have proposed that children possess a biological predisposition for language acquisition.

Starting before birth, babies begin to develop language and communication skills. At birth, babies apparently recognize their mother’s voice and can discriminate between the language(s) spoken by their mothers and foreign languages, and they show preferences for faces that are moving in synchrony with audible language (Blossom & Morgan, 2006; Pickens, 1994; Spelke & Cortelyou, 1981).

Children communicate information through gesturing long before they speak, and there is some evidence that gesture usage predicts subsequent language development (Iverson & Goldin-Meadow, 2005). In terms of producing spoken language, babies begin to coo almost immediately. Cooing is a one-syllable combination of a consonant and a vowel sound (e.g., coo or ba). Interestingly, babies replicate sounds from their own languages. A baby whose parents speak French will coo in a different tone than a baby whose parents speak Spanish or Urdu. After cooing, the baby starts to babble. Babbling begins with repeating a syllable, such as ma-ma, da-da, or ba-ba. When a baby is about 12 months old, we expect her to say her first word for meaning and to start combining words for meaning at about 18 months.

At about 2 years old, a toddler uses between 50 and 200 words; by 3 years old they have a vocabulary of up to 1,000 words and can speak in sentences. During the early childhood years, children’s vocabulary increases at a rapid pace. This is sometimes referred to as the “vocabulary spurt” and has been claimed to involve an expansion in vocabulary at a rate of 10–20 new words per week. Recent research may indicate that while some children experience these spurts, it is far from universal (as discussed in Ganger & Brent, 2004). It has been estimated that 5-year-olds understand about 6,000 words, speak 2,000 words, and can define words and question their meanings. They can rhyme and name the days of the week. Seven-year-olds speak fluently and use slang and clichés (Stork & Widdowson, 1974).

What accounts for such dramatic language learning by children? Behaviorist B. F. Skinner thought that we learn language in response to reinforcement or feedback, such as through parental approval or through being understood. For example, when a 2-year-old child asks for juice, he might say, “Me juice,” to which his mother might respond by giving him a cup of apple juice. Noam Chomsky (1957) criticized Skinner’s theory and proposed that we are all born with an innate capacity to learn language. Chomsky called this mechanism a language acquisition device (LAD). Who is correct? Both Chomsky and Skinner are right. Remember that we are a product of both nature and nurture. Researchers now believe that language acquisition is partially inborn and partially learned through our interactions with our linguistic environment (Gleitman & Newport, 1995; Stork & Widdowson, 1974).

Psychosocial development occurs as children form relationships, interact with others, and understand and manage their feelings . In social and emotional development, forming healthy attachments is very important and is the major social milestone of infancy. Attachment is a long-standing connection or bond with others. Developmental psychologists are interested in how infants reach this milestone. They ask such questions as: How do parent and infant attachment bonds form? How does neglect affect these bonds? What accounts for children’s attachment differences?

Researchers Harry Harlow, John Bowlby, and Mary Ainsworth conducted studies designed to answer these questions. In the 1950s, Harlow conducted a series of experiments on monkeys. He separated newborn monkeys from their mothers. Each monkey was presented with two surrogate mothers. One surrogate monkey was made out of wire mesh, and she could dispense milk. The other monkey was softer and made from cloth: This monkey did not dispense milk. Research shows that the monkeys preferred the soft, cuddly cloth monkey, even though she did not provide any nourishment. The baby monkeys spent their time clinging to the cloth monkey and only went to the wire monkey when they needed to be fed. Prior to this study, the medical and scientific communities generally thought that babies become attached to the people who provide their nourishment. However, Harlow (1958) concluded that there was more to the mother-child bond than nourishment. Feelings of comfort and security are the critical components of maternal-infant bonding, which leads to healthy psychosocial development.

Harlow’s studies of monkeys were performed before modern ethics guidelines were in place, and today his experiments are widely considered to be unethical and even cruel. Watch this video to see actual footage of Harlow’s monkey studies: Harlow’s Studies on Dependency in Monkeys .

Building on the work of Harlow and others, John Bowlby developed the concept of attachment theory. He defined attachment as the affectional bond or tie that an infant forms with the mother (Bowlby, 1969). An infant must form this bond with a primary caregiver in order to have normal social and emotional development. In addition, Bowlby proposed that this attachment bond is very powerful and continues throughout life. He used the concept of secure base to define a healthy attachment between parent and child (1988). A secure base is a parental presence that gives the child a sense of safety as he explores his surroundings. Bowlby said that two things are needed for a healthy attachment: The caregiver must be responsive to the child’s physical, social, and emotional needs; and the caregiver and child must engage in mutually enjoyable interactions (Bowlby, 1969).

While Bowlby thought attachment was an all-or-nothing process, Mary Ainsworth’s (1970) research showed otherwise. Ainsworth wanted to know if children differ in the ways they bond, and if so, why. To find the answers, she used the Strange Situation procedure to study attachment between mothers and their infants (1970). In the Strange Situation, the mother (or primary caregiver) and the infant (age 12-18 months) are placed in a room together. There are toys in the room, and the caregiver and child spend some time alone in the room. After the child has had time to explore her surroundings, a stranger enters the room. The mother then leaves her baby with the stranger. After a few minutes, she returns to comfort her child.

Based on how the infants/toddlers responded to the separation and reunion, Ainsworth identified three types of parent-child attachments : secure, avoidant, and resistant (Ainsworth & Bell, 1970). A fourth style, known as disorganized attachment, was later described (Main & Solomon, 1990). The most common type of attachment—also considered the healthiest—is called secure attachment . In this type of attachment, the toddler prefers his parent over a stranger . The attachment figure is used as a secure base to explore the environment and is sought out in times of stress. Securely attached children were distressed when their caregivers left the room in the Strange Situation experiment, but when their caregivers returned, the securely attached children were happy to see them. Securely attached children have caregivers who are sensitive and responsive to their needs.

With avoidant attachment , the child is unresponsive to the parent, does not use the parent as a secure base, and does not care if the parent leaves . The toddler reacts to the parent the same way she reacts to a stranger. When the parent does return, the child is slow to show a positive reaction. Ainsworth theorized that these children were most likely to have a caregiver who was insensitive and inattentive to their needs (Ainsworth, Blehar, Waters, & Wall, 1978).

In cases of resistant attachment , children tend to show clingy behavior, but then they reject the attachment figure’s attempts to interact with them (Ainsworth & Bell, 1970). These children do not explore the toys in the room, as they are too fearful. During separation in the Strange Situation, they became extremely disturbed and angry with the parent. When the parent returns, the children are difficult to comfort. Resistant attachment is the result of the caregivers’ inconsistent level of response to their child.

Finally, children with disorganized attachment behaved oddly in the Strange Situation. They freeze, run around the room in an erratic manner, or try to run away when the caregiver returns (Main & Solomon, 1990). This type of attachment is seen most often in kids who have been abused. Research has shown that abuse disrupts a child’s ability to regulate their emotions.

While Ainsworth’s research has found support in subsequent studies, it has also met criticism. Some researchers have pointed out that a child’s temperament may have a strong influence on attachment (Gervai, 2009; Harris, 2009), and others have noted that attachment varies from culture to culture, a factor not accounted for in Ainsworth’s research (Rothbaum, Weisz, Pott, Miyake, & Morelli, 2000; van Ijzendoorn & Sagi-Schwartz, 2008).

Watch this video to view a clip of the Strange Situation. Try to identify which type of attachment baby Lisa exhibits: The Strange Situation – Mary Ainsworth .

Self-Concept

Just as attachment is the main psychosocial milestone of infancy, the primary psychosocial milestone of childhood is the development of a positive sense of self. How does self-awareness develop? Infants don’t have a self-concept, which is an understanding of who they are. If you place a baby in front of a mirror, she will reach out to touch her image, thinking it is another baby. However, by about 18 months a toddler will recognize that the person in the mirror is herself. How do we know this? In a well-known experiment, a researcher placed a red dot of paint on children’s noses before putting them in front of a mirror (Amsterdam, 1972). Commonly known as the mirror test, this behavior is demonstrated by humans and a few other species and is considered evidence of self-recognition (Archer, 1992). At 18 months old they would touch their own noses when they saw the paint, surprised to see a spot on their faces. By 24–36 months old children can name and/or point to themselves in pictures, clearly indicating self-recognition.

Children from 2–4 years old display a great increase in social behavior once they have established a self-concept. They enjoy playing with other children, but they have difficulty sharing their possessions. Also, through play children explore and come to understand their gender roles and can label themselves as a girl or boy (Chick, Heilman-Houser, & Hunter, 2002). By 4 years old, children can cooperate with other children, share when asked, and separate from parents with little anxiety. Children at this age also exhibit autonomy , initiate tasks, and carry out plans . Success in these areas contributes to a positive sense of self . Once children reach 6 years old, they can identify themselves in terms of group memberships: “I’m a first grader!” School-age children compare themselves to their peers and discover that they are competent in some areas and less so in others (recall Erikson’s task of industry versus inferiority). At this age, children recognize their own personality traits as well as some other traits they would like to have. For example, 10-year-old Layla says, “I’m kind of shy. I wish I could be more talkative like my friend Alexa.”

Development of a positive self-concept is important to healthy development. Children with a positive self-concept tend to be more confident, do better in school, act more independently, and are more willing to try new activities (Maccoby, 1980; Ferrer & Fugate, 2003). Formation of a positive self-concept begins in Erikson’s toddlerhood stage, when children establish autonomy and become confident in their abilities. Development of self-concept continues in elementary school, when children compare themselves to others. When the comparison is favorable, children feel a sense of competence and are motivated to work harder and accomplish more. Self-concept is re-evaluated in Erikson’s adolescence stage, as teens form an identity. They internalize the messages they have received regarding their strengths and weaknesses, keeping some messages and rejecting others. Adolescents who have achieved identity formation are capable of contributing positively to society (Erikson, 1968).

What can parents do to nurture a healthy self-concept? Diana Baumrind (1971, 1991) thinks parenting style may be a factor. The way we parent is an important factor in a child’s socioemotional growth. Baumrind developed and refined a theory describing four parenting styles : authoritative, authoritarian, permissive, and uninvolved . With the authoritative style , the parent gives reasonable demands and consistent limits, expresses warmth and affection, and listens to the child’s point of view . Parents set rules and explain the reasons behind them. They are also flexible and willing to make exceptions to the rules in certain cases—for example, temporarily relaxing bedtime rules to allow for a nighttime swim during a family vacation. Of the four parenting styles, the authoritative style is the one that is most encouraged in modern American society. American children raised by authoritative parents tend to have high self-esteem and social skills. However, effective parenting styles vary as a function of culture and, as Small (1999) points out, the authoritative style is not necessarily preferred or appropriate in all cultures.

In authoritarian style , the parent places high value on conformity and obedience. The parents are often strict, tightly monitor their children, and express little warmth . In contrast to the authoritative style, authoritarian parents probably would not relax bedtime rules during a vacation because they consider the rules to be set, and they expect obedience. This style can create anxious, withdrawn, and unhappy kids. However, it is important to point out that authoritarian parenting is as beneficial as the authoritative style in some ethnic groups (Russell, Crockett, & Chao, 2010). For instance, first-generation Chinese American children raised by authoritarian parents did just as well in school as their peers who were raised by authoritative parents (Russell et al., 2010).

For parents who employ the permissive style of parenting , the kids run the show and anything goes. Permissive parents make few demands and rarely use punishment . They tend to be very nurturing and loving and may play the role of friend rather than parent. In terms of our example of vacation bedtimes, permissive parents might not have bedtime rules at all—instead they allow the child to choose his bedtime whether on vacation or not. Not surprisingly, children raised by permissive parents tend to lack self-discipline, and the permissive parenting style is negatively associated with grades (Dornbusch, Ritter, Leiderman, Roberts, & Fraleigh, 1987). The permissive style may also contribute to other risky behaviors such as alcohol abuse (Bahr & Hoffman, 2010), risky sexual behavior especially among female children (Donenberg, Wilson, Emerson, & Bryant, 2002), and increased display of disruptive behaviors by male children (Parent et al., 2011). However, there are some positive outcomes associated with children raised by permissive parents. They tend to have higher self-esteem, better social skills, and report lower levels of depression (Darling, 1999).

With the uninvolved style of parenting , the parents are indifferent, uninvolved, and sometimes referred to as neglectful. They don’t respond to the child’s needs and make relatively few demands . This could be because of severe depression or substance abuse, or other factors such as the parents’ extreme focus on work. These parents may provide for the child’s basic needs, but little else. The children raised in this parenting style are usually emotionally withdrawn, fearful, anxious, perform poorly in school, and are at an increased risk of substance abuse (Darling, 1999).

As you can see, parenting styles influence childhood adjustment, but could a child’s temperament likewise influence parenting? Temperament refers to innate traits that influence how one thinks, behaves, and reacts with their environment. Children with easy temperaments demonstrate positive emotions, adapt well to change, and are capable of regulating their emotions. Conversely, children with difficult temperaments demonstrate negative emotions and have difficulty adapting to change and regulating their emotions. Difficult children are much more likely to challenge parents, teachers, and other caregivers (Thomas, 1984). Therefore, it’s possible that easy children (i.e., social, adaptable, and easy to soothe) tend to elicit warm and responsive parenting, while demanding, irritable, withdrawn children evoke irritation in their parents or cause their parents to withdraw (Sanson & Rothbart, 1995).

According to the American Academy of Pediatrics (2007), unstructured play is an integral part of a child’s development. It builds creativity, problem-solving skills, and social relationships. Play also allows children to develop a theory-of-mind as they imaginatively take on the perspective of others.

Outdoor play allows children the opportunity to directly experience and sense the world around them. While doing so, they may collect objects that they come across and develop lifelong interests and hobbies. They also benefit from increased exercise, and engaging in outdoor play can actually increase how much they enjoy physical activity. This helps support the development of a healthy heart and brain. Unfortunately, research suggests that today’s children are engaging in less and less outdoor play (Clements, 2004). Perhaps, it is no surprise to learn that lowered levels of physical activity in conjunction with easy access to calorie-dense foods with little nutritional value are contributing to alarming levels of childhood obesity (Karnik & Kanekar, 2012).

Despite the adverse consequences associated with reduced play, some children are over-scheduled and have little free time to engage in unstructured play. In addition, some schools have taken away recess time for children in a push for students to do better on standardized tests, and many schools commonly use loss of recess as a form of punishment. Do you agree with these practices? Why or why not?

Adolescence

Adolescence is a socially constructed concept. In pre-industrial society, children were considered adults when they reached physical maturity, but today we have an extended time between childhood and adulthood called adolescence. Adolescence is the period of development that begins at puberty and ends at emerging adulthood , which is discussed later. In the United States, adolescence is seen as a time to develop independence from parents while remaining connected to them. The typical age range of adolescence is from 12 to 18 years, and this stage of development also has some predictable physical, cognitive, and psychosocial milestones.

As noted above, adolescence begins with puberty. While the sequence of physical changes in puberty is predictable, the onset and pace of puberty vary widely. Several physical changes occur during puberty, such as adrenarche and gonadarche , the maturing of the adrenal glands and sex glands, respectively . Also during this time, primary and secondary sexual characteristics develop and mature. Primary sexual characteristics are organs specifically needed for reproduction, like the uterus and ovaries in females and testes in males . Secondary sexual characteristics are physical signs of sexual maturation that do not directly involve sex organs, such as development of breasts and hips in girls, and development of facial hair and a deepened voice in boys . Girls experience menarche , the beginning of menstrual periods, usually around 12–13 years old , and boys experience spermarche , the first ejaculation, around 13–14 years old .

During puberty, both sexes experience a rapid increase in height (i.e., growth spurt). For girls this begins between 8 and 13 years old, with adult height reached between 10 and 16 years old. Boys begin their growth spurt slightly later, usually between 10 and 16 years old, and reach their adult height between 13 and 17 years old. Both nature (i.e., genes) and nurture (e.g., nutrition, medications, and medical conditions) can influence height.

Because rates of physical development vary so widely among teenagers, puberty can be a source of pride or embarrassment. Early maturing boys tend to be stronger, taller, and more athletic than their later maturing peers. They are usually more popular, confident, and independent, but they are also at a greater risk for substance abuse and early sexual activity (Flannery, Rowe, & Gulley, 1993; Kaltiala-Heino, Rimpela, Rissanen, & Rantanen, 2001). Early maturing girls may be teased or overtly admired, which can cause them to feel self-conscious about their developing bodies. These girls are at a higher risk for depression, substance abuse, and eating disorders (Ge, Conger, & Elder, 2001; Graber, Lewinsohn, Seeley, & Brooks-Gunn, 1997; Striegel-Moore & Cachelin, 1999). Late-blooming boys and girls (i.e., they develop more slowly than their peers) may feel self-conscious about their lack of physical development. Negative feelings are particularly a problem for late-maturing boys, who are at a higher risk for depression and conflict with parents (Graber et al., 1997) and are more likely to be bullied (Pollack & Shuster, 2000).

The adolescent brain also remains under development. Up until puberty, brain cells continue to bloom in the frontal region. Adolescents engage in increased risk-taking behaviors and emotional outbursts possibly because the frontal lobes of their brains are still developing. Recall that this area is responsible for judgment, impulse control, and planning, and it is still maturing into early adulthood (Casey, Tottenham, Liston, & Durston, 2005).

More complex thinking abilities emerge during adolescence. Some researchers suggest this is due to increases in processing speed and efficiency rather than as the result of an increase in mental capacity—in other words, due to improvements in existing skills rather than the development of new ones (Bjorkland, 1987; Case, 1985). During adolescence, teenagers move beyond concrete thinking and become capable of abstract thought. Recall that Piaget refers to this stage as formal operational thought. Teen thinking is also characterized by the ability to consider multiple points of view, imagine hypothetical situations, debate ideas and opinions (e.g., politics, religion, and justice), and form new ideas. In addition, it’s not uncommon for adolescents to question authority or challenge established societal norms.

Cognitive empathy , also known as theory-of-mind (which we discussed earlier with regard to egocentrism), relates to the ability to take the perspective of others and feel concern for others (Shamay-Tsoory, Tomer, & Aharon-Peretz, 2005). Cognitive empathy begins to increase in adolescence and is an important component of social problem-solving and conflict avoidance. According to one longitudinal study, levels of cognitive empathy begin rising in girls around 13 years old and around 15 years old in boys (Van der Graaff et al., 2013). Teens who reported having supportive fathers with whom they could discuss their worries were found to be better able to take the perspective of others (Miklikowska, Duriez, & Soenens, 2011).

Psychosocial Development

Adolescents continue to refine their sense of self as they relate to others. Erikson referred to the task of the adolescent as one of identity versus role confusion. Thus, in Erikson’s view, an adolescent’s main questions are “Who am I?” and “Who do I want to be?” Some adolescents adopt the values and roles that their parents expect from them. Other teens develop identities that are in opposition to their parents but align with a peer group. This is common as peer relationships become a central focus in adolescents’ lives.

As adolescents work to form their identities, they pull away from their parents, and the peer group becomes very important (Shanahan, McHale, Osgood, & Crouter, 2007). Despite spending less time with their parents, most teens report positive feelings toward them (Moore, Guzman, Hair, Lippman, & Garrett, 2004). Warm and healthy parent-child relationships have been associated with positive child outcomes, such as better grades and fewer school behavior problems, in the United States as well as in other countries (Hair et al., 2005).

It appears that most teens don’t experience adolescent storm and stress to the degree once famously suggested by G. Stanley Hall , a pioneer in the study of adolescent development . Only a small number of teens have major conflicts with their parents (Steinberg & Morris, 2001), and most disagreements are minor. For example, in a study of over 1,800 parents of adolescents from various cultural and ethnic groups, Barber (1994) found that conflicts occurred over day-to-day issues such as homework, money, curfews, clothing, chores, and friends. These types of arguments tend to decrease as teens develop (Galambos & Almeida, 1992).

Emerging Adulthood

The next stage of development is emerging adulthood . This is a relatively newly defined period of lifespan development spanning from 18 years old to the mid-20s, characterized as an in-between time where identity exploration is focused on work and love .

When does a person become an adult? There are many ways to answer this question. In the United States, you are legally considered an adult at 18 years old. But other definitions of adulthood vary widely; in sociology, for example, a person may be considered an adult when she becomes self-supporting, chooses a career, gets married, or starts a family. The ages at which we achieve these milestones vary from person to person as well as from culture to culture. For example, in the African country of Malawi, 15-year-old Njemile was married at 14 years old and had her first child at 15 years old. In her culture she is considered an adult. Children in Malawi take on adult responsibilities such as marriage and work (e.g., carrying water, tending babies, and working fields) as early as 10 years old. In stark contrast, independence in Western cultures is taking longer and longer, effectively delaying the onset of adult life.

Why is it taking twentysomethings so long to grow up? It seems that emerging adulthood is a product of both Western culture and our current times (Arnett, 2000). People in developed countries are living longer, allowing the freedom to take an extra decade to start a career and family. Changes in the workforce also play a role. For example, 50 years ago, a young adult with a high school diploma could immediately enter the workforce and climb the corporate ladder. That is no longer the case. Bachelor’s and even graduate degrees are required more and more often—even for entry-level jobs (Arnett, 2000). In addition, many students are taking longer (5 or 6 years) to complete a college degree as a result of working and going to school at the same time. After graduation, many young adults return to the family home because they have difficulty finding a job. Changing cultural expectations may be the most important reason for the delay in entering adult roles. Young people are spending more time exploring their options, so they are delaying marriage and work as they change majors and jobs multiple times, putting them on a much later timetable than their parents (Arnett, 2000).

Adulthood begins around 20 years old and has three distinct stages: early, middle, and late . Each stage brings its own set of rewards and challenges.

By the time we reach early adulthood (20 to early 40s), our physical maturation is complete, although our height and weight may increase slightly. In young adulthood, our physical abilities are at their peak, including muscle strength, reaction time, sensory abilities, and cardiac functioning. Most professional athletes are at the top of their game during this stage. Many women have children in the young adulthood years, so they may see additional weight gain and breast changes.

Middle adulthood extends from the 40s to the 60s . Physical decline is gradual. The skin loses some elasticity, and wrinkles are among the first signs of aging. Visual acuity decreases during this time. Women experience a gradual decline in fertility as they approach the onset of menopause , the end of the menstrual cycle, around 50 years old . Both men and women tend to gain weight: in the abdominal area for men and in the hips and thighs for women. Hair begins to thin and turn gray.

Late adulthood is considered to extend from the 60s on. This is the last stage of physical change. The skin continues to lose elasticity, reaction time slows further, and muscle strength diminishes. Smell, taste, hearing, and vision, so sharp in our 20s, decline significantly. The brain may also no longer function at optimal levels, leading to problems like memory loss, dementia, and Alzheimer’s disease in later years.

Aging doesn’t mean a person can’t explore new pursuits, learn new skills, and continue to grow. Watch this inspiring story about Neal Unger, who is a newbie to the world of skateboarding at 60 years old: NEAL UNGER – 60 YEAR OLD SKATEBOARDER .

Because we spend so many years in adulthood (more than any other stage), cognitive changes are numerous. In fact, research suggests that adult cognitive development is a complex, ever-changing process that may be even more active than cognitive development in infancy and early childhood (Fischer, Yan, & Stewart, 2003).

There is good news for the middle age brain. View this brief video to find out what it is: Middle Age Brains – NJN News Healthwatch Report .

Unlike our physical abilities, which peak in our mid-20s and then begin a slow decline, our cognitive abilities remain steady throughout early and middle adulthood. Our crystallized intelligence ( information, skills, and strategies we have gathered through a lifetime of experience ) tends to hold steady as we age—it may even improve. For example, adults show relatively stable to increasing scores on intelligence tests until their mid-30s to mid-50s (Bayley & Oden, 1955). However, in late adulthood we begin to experience a decline in another area of our cognitive abilities— fluid intelligence ( information processing abilities, reasoning, and memory ). These processes become slower. How can we delay the onset of cognitive decline? Mental and physical activity seem to play a part. Research has found adults who engage in mentally and physically stimulating activities experience less cognitive decline and have a reduced incidence of mild cognitive impairment and dementia (Hertzog, Kramer, Wilson, & Lindenberger, 2009; Larson et al., 2006; Podewils et al., 2005).

There are many theories about the social and emotional aspects of aging. Some aspects of healthy aging include activities, social connectedness, and the role of a person’s culture. According to many theorists, including George Vaillant (2002), who studied and analyzed over 50 years of data, we need to have and continue to find meaning throughout our lives. For those in early and middle adulthood, meaning is found through work (Sterns & Huyck, 2001) and family life (Markus, Ryff, Curan, & Palmersheim, 2004). These areas relate to the tasks that Erikson referred to as generativity and intimacy. As mentioned previously, adults tend to define themselves by what they do—their careers. Earnings peak during this time, yet job satisfaction is more closely tied to work that involves contact with other people, is interesting, provides opportunities for advancement, and allows some independence (Mohr & Zoghi, 2006) than it is to salary (Iyengar, Wells, & Schwartz, 2006). How might being unemployed or being in a dead-end job challenge adult well-being?

Positive relationships with significant others in our adult years have been found to contribute to a state of well-being (Ryff & Singer, 2009). Most adults in the United States identify themselves through their relationships with family—particularly with spouses, children, and parents (Markus et al., 2004). While raising children can be stressful, especially when they are young, research suggests that parents reap the rewards down the road, as adult children tend to have a positive effect on parental well-being (Umberson, Pudrovska, & Reczek, 2010). Having a stable marriage has also been found to contribute to well-being throughout adulthood (Vaillant, 2002).

Another aspect of positive aging is believed to be social connectedness and social support. As we get older, socioemotional selectivity theory suggests that our social support and friendships dwindle in number but remain as close, if not closer, than in our earlier years (Carstensen, 1992).

To learn more, view this video on aging in America: The Many Faces of Aging In America .

At conception, the egg and sperm cell are united to form a zygote, which will begin to divide rapidly. This marks the beginning of the first stage of prenatal development (germinal stage), which lasts about 2 weeks. Then the zygote implants itself into the lining of the woman’s uterus, marking the beginning of the second stage of prenatal development (embryonic stage), which lasts about 6 weeks. The embryo begins to develop body and organ structures, and the neural tube forms, which will later become the brain and spinal cord. The third phase of prenatal development (fetal stage) begins at 9 weeks and lasts until birth. The body, brain, and organs grow rapidly during this stage. During all stages of pregnancy it is important that the mother receive prenatal care to reduce health risks to herself and to her developing baby.

Newborn infants weigh about 7.5 pounds. Doctors assess a newborn’s reflexes, such as the sucking, rooting, and Moro reflexes. Our physical, cognitive, and psychosocial skills grow and change as we move through developmental stages from infancy through late adulthood. Attachment in infancy is a critical component of healthy development. Parenting styles have been found to have an effect on childhood outcomes of well-being. The transition from adolescence to adulthood can be challenging due to the timing of puberty, and due to the extended amount of time spent in emerging adulthood. Although physical decline begins in middle adulthood, cognitive decline does not begin until later. Activities that keep the body and mind active can help maintain good physical and cognitive health as we age. Social supports through family and friends remain important as we age.

Review Questions

Critical thinking questions.

Alcohol is a teratogen. Excessive drinking can cause intellectual disabilities in children. The child can also have a small head and abnormal facial features, which are characteristic of fetal alcohol syndrome (FAS). Another teratogen is nicotine. Smoking while pregnant can lead to low-birth weight, premature birth, stillbirth, and SIDS.

Prenatal care is medical care during pregnancy that monitors the health of both the mother and fetus. It’s important to receive prenatal care because it can reduce complications to the mother and fetus during pregnancy.

In the embryonic stage, basic structures of the embryo start to develop into areas that will become the head, chest, and abdomen. The heart begins to beat and organs form and begin to function. The neural tube forms along the back of the embryo, developing into the spinal cord and brain. In the fetal stage, the brain and body continue to develop. Fingers and toes develop along with hearing, and internal organs form.

The particular quality or trait must be part of an enduring behavior pattern, so that it is a consistent or predictable quality.

The sucking reflex is the automatic, unlearned sucking motions that infants do with their mouths. It may help promote survival because this action helps the baby take in nourishment. The rooting reflex is the newborn’s response to anything that touches her cheek. When you stroke a baby’s cheek, she will naturally turn her head that way and begin to suck. This may aid survival because it helps the newborn locate a source of food.

With the authoritative style, children are given reasonable demands and consistent limits, warmth and affection are expressed, the parent listens to the child’s point of view, and the child initiates positive standards. Children raised by authoritative parents tend to have high self-esteem and social skills. Another parenting style is authoritarian: The parent places a high value on conformity and obedience. The parents are often strict, tightly monitor their children, and express little warmth. This style can create anxious, withdrawn, and unhappy kids. The third parenting style is permissive: Parents make few demands, rarely use punishment, and give their children free rein. Children raised by permissive parents tend to lack self-discipline, which contributes to poor grades and alcohol abuse. However, they have higher self-esteem, better social skills, and lower levels of depression. The fourth style is the uninvolved parent: They are indifferent, uninvolved, and sometimes called neglectful. The children raised in this parenting style are usually emotionally withdrawn, fearful, anxious, perform poorly in school, and are at an increased risk of substance abuse.

Emerging adulthood is a relatively new period of lifespan development from 18 years old to the mid-20s, characterized as a transitional time in which identity exploration focuses on work and love. According to Arnett, changing cultural expectations facilitate the delay to full adulthood. People are spending more time exploring their options, so they are delaying marriage and work as they change majors and jobs multiple times, putting them on a much later timetable than their parents.

Personal Application Questions

• Which parenting style describes how you were raised? Provide an example or two to support your answer.
• Would you describe your experience of puberty as one of pride or embarrassment? Why?
• Your best friend is a smoker who just found out she is pregnant. What would you tell her about smoking and pregnancy?
• Imagine you are a nurse working at a clinic that provides prenatal care for pregnant women. Your patient, Anna, has heard that it’s a good idea to play music for her unborn baby, and she wants to know when her baby’s hearing will develop. What will you tell her?

occurs when sperm fertilizes an egg and forms a zygote

begins as a one-cell structure that is created when a sperm and egg merge

process of cell division

the mass of cells has yet to attach itself to the lining of the mother’s uterus

a structure connected to the uterus that provides nourishment and oxygen from the mother to the developing embryo via the umbilical cord

the heart begins to beat and organs form and begin to function

When the organism is about nine weeks old

any environmental agent—biological, chemical, or physical—that causes damage to the developing embryo or fetus

a collection of birth defects associated with heavy consumption of alcohol during pregnancy. Physically, children with FASD may have a small head size and abnormal facial features. Cognitively, these children may have poor judgment, poor impulse control, higher rates of ADHD, learning issues, and lower IQ scores

period of rapid neural growth

refer to our ability to move our bodies and manipulate objects

focus on the muscles in our fingers, toes, and eyes, and enable coordination of small actions (e.g., grasping a toy, writing with a pencil, and using a spoon)

focus on large muscle groups that control our arms and legs and involve larger movements (e.g., balancing, running, and jumping)

occurs as children form relationships, interact with others, and understand and manage their feelings

the affectional bond or tie that an infant forms with the mother

secure, avoidant, and resistant

the toddler prefers his parent over a stranger

the child is unresponsive to the parent, does not use the parent as a secure base, and does not care if the parent leaves

children tend to show clingy behavior, but then they reject the attachment figure’s attempts to interact with them

initiate tasks, and carry out plans. contributes to a positive sense of self.

authoritative, authoritarian, permissive, and uninvolved

the parent gives reasonable demands and consistent limits, expresses warmth and affection, and listens to the child’s point of view

the parent places high value on conformity and obedience. The parents are often strict, tightly monitor their children, and express little warmth

the kids run the show and anything goes. Permissive parents make few demands and rarely use punishment

the parents are indifferent, uninvolved, and sometimes referred to as neglectful. They don’t respond to the child’s needs and make relatively few demands

refers to innate traits that influence how one thinks, behaves, and reacts with the environment

the period of development that begins at puberty and ends at emerging adulthood

the maturing of the adrenal glands and sex glands, respectively

are organs specifically needed for reproduction, like the uterus and ovaries in females and testes in males

are physical signs of sexual maturation that do not directly involve sex organs, such as development of breasts and hips in girls, and development of facial hair and a deepened voice in boys

the beginning of menstrual periods, usually around 12–13 years old

the first ejaculation, around 13–14 years old

theory-of-mind, relates to the ability to take the perspective of others and feel concern for others

a pioneer in the study of adolescent development

relatively newly defined period of lifespan development spanning from 18 years old to the mid-20s, characterized as an in-between time where identity exploration is focused on work and love

begins around 20 years old and has three distinct stages: early, middle, and late

extends from the 40s to the 60s

the end of the menstrual cycle, around 50 years old

information, skills, and strategies we have gathered through a lifetime of experience

information processing abilities, reasoning, and memory

Stages of Human Development Copyright © 2022 by LOUIS: The Louisiana Library Network is licensed under a Creative Commons Attribution 4.0 International License , except where otherwise noted.

Share This Book

Intro to Lifespan Development

Why study lifespan development.

Welcome to the study of lifespan development! This is the scientific study of how and why people change or remain the same over time.

Think about how you were five, ten, or even fifteen years ago. In what ways have you changed? In what ways have you remained the same? You have probably changed physically; perhaps you’ve grown taller and become heavier. But you may have also experienced changes in the way you think and solve problems. Cognitive change is noticeable when we compare how 6-year olds, 16-year olds, and 46-year olds think and reason, for example. Their thoughts about themselves, others, and the world are probably quite different. Consider friendship—a 6-year-old may think that a friend is someone with whom they can play and have fun. A 16-year old may seek friends who can help them gain status or popularity. And the 46-year old may have acquaintances, but rely more on family members to do things with and confide in. You may have also experienced psychosocial change. This refers to emotions and psychological issues as well as social roles and relationships. Psychologist Erik Erikson suggests that we struggle with issues of trust, independence, and intimacy at various points in our lives (we will explore this thoroughly throughout the course.)

This is a very interesting and meaningful course because it is about each of us and those with whom we live and work. One of the best ways to gain perspective on our own lives is to compare our experiences with those of others. In this course, we will strive to learn about each phase of human development and the physical, cognitive, and psychosocial changes, all the while making cross-cultural and historical comparisons and connections to the world around us.

In addition, we will take a lifespan developmental approach to learn about human development. That means that we won’t just learn about one particular age period by itself; we will learn about each age period, recognizing how it is related to both previous developments and later developments. For instance, it helps us to understand what’s happening with the 16-year old by knowing about development in the infant, toddler, early childhood, and middle childhood years. In turn, learning about all of that development and development during adolescence and early adulthood will help us to more fully understand the person at age 46 (and so on throughout midlife and later adulthood).

Development does not stop at a certain age; development is a lifelong process. We may find individual and group differences in patterns of development, so examining the influences of gender, cohort/generation, race, ethnicity, culture, socioeconomic status, education level, and time in history is also important. With the lifespan developmental perspective, we will gain a more comprehensive view of the individual within the context of their own developmental journey and within social, cultural, and historical contexts. In this way, this course covers and crosses multiple disciplines, such as psychology, biology, sociology, anthropology, education, nutrition, economics, and healthcare.

Think It Over

Wherever you are in your own lifespan developmental journey, imagine yourself as an elderly person about to turn 100 years old (becoming a “centenarian”). If researchers want to understand you and your development, would they get the full picture if they just took a snapshot (so to speak) of you at that point in time? What else would you want them to know about you, your development, and your experiences to really understand you?

What you’ll learn to do: define human development and identify the stages of human development

What aspects of ourselves change and develop as we journey through life? We move through significant physical, cognitive, and psychosocial changes throughout our lives—do these changes happen in a systematic way, and to everyone? How much is due to genetics and how much is due to environmental influences and experiences (both within our personal control and beyond)? Is there just one course of development or are there many different courses of development? In this module, we’ll examine these questions and learn about the major stages of development and what kind of developmental tasks and transitions we might expect along the way.

Learning Outcomes

• Describe human development and its three domains: physical, cognitive, and psychosocial development
• Explain key human development issues about the nature of change: continuous/discontinuous, one course/multiple courses, and nature/nurture
• Describe the basic periods of human development

Defining Human Development

Human development refers to the physical, cognitive, and psychosocial development of humans throughout the lifespan. What types of development are involved in each of these three domains, or areas, of life? Physical development involves growth and changes in the body and brain, the senses, motor skills, and health and wellness. Cognitive development involves learning, attention, memory, language, thinking, reasoning, and creativity. Psychosocial development involves emotions, personality, and social relationships.

Physical Domain

Many of us are familiar with the height and weight charts that pediatricians consult to estimate if babies, children, and teens are growing within normative ranges of physical development. We may also be aware of changes in children’s fine and gross motor skills, as well as their increasing coordination, particularly in terms of playing sports. But we may not realize that physical development also involves brain development, which not only enables childhood motor coordination but also greater coordination between emotions and planning in adulthood, as our brains are not done developing in infancy or childhood. Physical development also includes puberty, sexual health, fertility, menopause, changes in our senses, and primary versus secondary aging. Healthy habits with nutrition and exercise are also important at every age and stage across the lifespan.

Cognitive Domain

If we watch and listen to infants and toddlers, we can’t help but wonder how they learn so much so fast, particularly when it comes to language development. Then as we compare young children to those in middle childhood, there appear to be huge differences in their ability to think logically about the concrete world around them. Cognitive development includes mental processes, thinking, learning, and understanding, and it doesn’t stop in childhood. Adolescents develop the ability to think logically about the abstract world (and may like to debate matters with adults as they exercise their new cognitive skills!). Moral reasoning develops further, as does practical intelligence—wisdom may develop with experience over time. Memory abilities and different forms of intelligence tend to change with age. Brain development and the brain’s ability to change and compensate for losses is significant to cognitive functions across the lifespan, too.

Psychosocial Domain

Development in this domain involves what’s going on both psychologically and socially. Early on, the focus is on infants and caregivers, as temperament and attachment are significant. As the social world expands and the child grows psychologically, different types of play, and interactions with other children and teachers become important. Psychosocial development involves emotions, personality, self-esteem, and relationships. Peers become more important for adolescents, who are exploring new roles and forming their own identities. Dating, romance, cohabitation, marriage, having children, and finding work or a career are all parts of the transition into adulthood. Psychosocial development continues across adulthood with similar (and some different) developmental issues of family, friends, parenting, romance, divorce, remarriage, blended families, caregiving for elders, becoming grandparents and great grandparents, retirement, new careers, coping with losses, and death and dying.

As you may have already noticed, physical, cognitive, and psychosocial development are often interrelated, as with the example of brain development. We will be examining human development in these three domains in detail throughout the modules in this course, as we learn about infancy/toddlerhood, early childhood, middle childhood, adolescence, young adulthood, middle adulthood, and late adulthood development, as well as death and dying.

Who Studies Human Development and Why?

Many academic disciplines contribute to the study of development and this type is offered in some schools as psychology (particularly as developmental psychology); in other schools, it is taught under sociology, human development, or family studies. This multidisciplinary course is made up of contributions from researchers in the areas of health care, anthropology, nutrition, child development, biology, gerontology, psychology, and sociology, among others. Consequently, the stories provided are rich and well-rounded and the theories and findings can be part of a collaborative effort to understand human lives.

The main goals of those involved in studying human development are to describe and explain changes. Throughout this course, we will describe observations during development, then examine how theories provide explanations for why these changes occur. For example, you may observe two-year-old children be particularly temperamental, and researchers offer theories to explain why that is. We’ll learn a lot more about theories, especially developmental theories, in the next module.

What you’ll learn to do: describe the theories of lifespan development

Learning outcomes

• Describe theories as they relate to lifespan development
• Explain Bronfenbrenner’s bioecological model
• Contrast the main psychological theories that apply to human development

Understanding Theories

In l ifespan development, we need to rely on a systematic approach to understanding behavior, based on observable events and the scientific method. There are so many different observations about childhood, adulthood, and development in general that we use theories to help organize all of the different observable events or variables. A theory is a simplified explanation of the world that attempts to explain how variables interact with each other. It can take complex, interconnected issues and narrow them down to the essentials. This enables developmental theorists and researchers to analyze the problem in greater depth.

Two key concepts in the scientific approach are theory and hypothesis. A theory is a well-developed set of ideas that propose an explanation for observed phenomena that can be used to make predictions about future observations. A hypothesis is a testable prediction that is arrived at logically from a theory. It is often worded as an if-then statement (e.g., if I study all night, I will get a passing grade on the test). The hypothesis is extremely important because it bridges the gap between the realm of ideas and the real world. As specific hypotheses are tested, theories are modified and refined to reflect and incorporate the result of these tests. In essence, lifespan theories explain observable events in a meaningful way. They are not as specific as hypotheses, which are so specific that we use them to make predictions in research. Theories offer more general explanations about behavior and events.

Think of theories are guidelines much like directions that come with an appliance or other object that required assembly. The instructions can help one piece together smaller parts more easily than if trial and error are used.

Theories can be developed using induction, in which a number of single cases are observed and after patterns or similarities are noted, the theorist develops ideas based on these examples. Established theories are then tested through research; however, not all theories are equally suited to scientific investigation.  Some theories are difficult to test but are still useful in stimulating debate or providing concepts that have practical application. Keep in mind that theories are not facts; they are guidelines for investigation and practice, and they gain credibility through research that fails to disprove them.

People who study lifespan development approach it from different perspectives. Each perspective encompasses one or more theories—the broad, organized explanations and predictions concerning phenomena of interest. Theories of development provide a framework for thinking about human growth, development, and learning. If you have ever wondered about what motivates human thought and behavior, understanding these theories can provide useful insight into individuals and society.

Throughout psychological history and still in the present day, three key issues remain among which developmental theorists often disagree. Particularly oft-disputed is the role of early experiences on later development in opposition to current behavior reflecting present experiences–namely the passive versus active issue . Likewise, whether or not development is best viewed as occurring in stages or rather as a gradual and cumulative process of change has traditionally been up for debate – a question of continuity versus discontinuity. Further, the role of heredity and the environment in shaping human development is a much-contested topic of discussion – also referred to as the nature/nurture debate . 

Is Development Continuous or Discontinuous?

Continuous development views development as a cumulative process, gradually improving on existing skills (Figure 2). With this type of development, there is a gradual change. Consider, for example, a child’s physical growth: adding inches to their height year by year. In contrast, theorists who view development as discontinuous believe that development takes place in unique stages and that it occurs at specific times or ages. With this type of development, the change is more sudden, such as an infant’s ability to demonstrate awareness of object permanence (which is a cognitive skill that develops toward the end of infancy, according to Piaget’s cognitive theory—more on that theory in the next module).

Is There One Course of Development or Many?

Is development essentially the same, or universal, for all children (i.e., there is one course of development) or does development follow a different course for each child, depending on the child’s specific genetics and environment (i.e., there are many courses of development)? Do people across the world share more similarities or more differences in their development? How much do culture and genetics influence a child’s behavior?

Stage theories hold that the sequence of development is universal. For example, in cross-cultural studies of language development, children from around the world reach language milestones in a similar sequence (Gleitman & Newport, 1995). Infants in all cultures coo before they babble. They begin babbling at about the same age and utter their first word around 12 months old. Yet we live in diverse contexts that have a unique effect on each of us. For example, researchers once believed that motor development followed one course for all children regardless of culture. However, childcare practices vary by culture, and different practices have been found to accelerate or inhibit the achievement of developmental milestones such as sitting, crawling, and walking (Karasik, Adolph, Tamis-LeMonda, & Bornstein, 2010).

For instance, let’s look at the Aché society in Paraguay. They spend a significant amount of time foraging in forests. While foraging, Aché mothers carry their young children, rarely putting them down in order to protect them from getting hurt in the forest. Consequently, their children walk much later: They walk around 23–25 months old, in comparison to infants in Western cultures who begin to walk around 12 months old. However, as Aché children become older, they are allowed more freedom to move about, and by about age 9, their motor skills surpass those of U.S. children of the same age: Aché children are able to climb trees up to 25 feet tall and use machetes to chop their way through the forest (Kaplan & Dove, 1987). As you can see, our development is influenced by multiple contexts, so the timing of basic motor functions may vary across cultures. However, the functions are present in all societies.

How Do Nature and Nurture Influence Development?

Are we who we are because of nature (biology and genetics), or are we who we are because of nurture (our environment and culture)? This longstanding question is known in psychology as the nature versus nurture debate. It seeks to understand how our personalities and traits are the product of our genetic makeup and biological factors, and how they are shaped by our environment, including our parents, peers, and culture. For instance, why do biological children sometimes act like their parents—is it because of genetics or because of early childhood environment and what the child has learned from their parents? What about children who are adopted—are they more like their biological families or more like their adoptive families? And how can siblings from the same family be so different?

We are all born with specific genetic traits inherited from our parents, such as eye color, height, and certain personality traits. Beyond our basic genotype, however, there is a deep interaction between our genes and our environment. Our unique experiences in our environment influence whether and how particular traits are expressed, and at the same time, our genes influence how we interact with our environment (Diamond, 2009; Lobo, 2008). There is a reciprocal interaction between nature and nurture as they both shape who we become, but the debate continues as to the relative contributions of each.

History of Developmental Psychology

The scientific study of children began in the late nineteenth century and blossomed in the early twentieth century as pioneering psychologists sought to uncover the secrets of human behavior by studying its development.

Early scholars John Locke and Charles Darwin proposed theories of human behavior that are the “direct ancestors of some major theoretical traditions” of developmental psychology today(Vasta et al., 1998, p. 10). Locke, a British empiricist, adhered to a strict environmentalist position. He saw the newborn’s mind as a tabula rasa (“blank slate”) on which knowledge is written through experience and learning.  Finally, the work of Darwin, the British biologist famous for his theory of evolution, led others to suggest that development proceeds through evolutionary recapitulation, with many human behaviors having their origins in successful adaptations in the past.

John B. Watson

The 20th century marked the formation of qualitative distinctions between children and adults. When John Watson wrote the book Psychological Care of Infant and Child in 1928, he sought to add clarification surrounding behaviorists’ views on child care and development. Watson was the founder of the field of behaviorism, which emphasized the role of nurture, or the environment, in human development. He believed, based on Locke’s environmentalist position, that human behavior can be understood in terms of experiences and learning. He believed that all behaviors are learned, or conditioned, as evidenced by his famous “Little Albert” study, in which he conditioned an infant to fear a white rat. In Watson’s book on the care of the infant and child, Watson explained that children should be treated as a young adult—with respect, but also without emotional attachment. In the book, he warned against the inevitable dangers of a mother providing too much love and affection. Watson explained that love, along with everything else as the behaviorist saw the world, is conditioned. Watson supported his warnings by mentioning invalidism, saying that society does not overly comfort children as they become young adults in the real world, so parents should not set up these unrealistic expectations. His book became highly criticized but was still influential in promoting more research into early childhood behavior and development.

Sigmund Freud

Another name you are probably familiar with who was influential in the study of human development is Sigmund Freud. Sigmund Freud’s model of “psychosexual development” grew out of his psychoanalytic approach to human personality and psychopathology. In sharp contrast to the objective approach espoused by Watson, Freud based his model of child development on his own and his patients’ recollections of their childhood. He developed a stage model of development in which the libido, or sexual energy, of the child, focuses on different “zones” or areas of the body as the child grows to adulthood. Freud’s model is an “interactionist” one since he believed that although the sequence and timing of these stages are biologically determined, successful personality development depends on the experiences the child has during each stage. Although the details of Freud’s developmental theory have been widely criticized, his emphasis on the importance of early childhood experiences, prior to five years of age, has had a lasting impact.

Freud emphasized the importance of early childhood experiences in shaping our personality and behavior. In our natural state, we are biological beings. We are driven primarily by instincts. During childhood, however, we begin to become social beings as we learn how to manage our instincts and transform them into socially acceptable behaviors. The type of parenting the child receives has a very powerful impact on the child’s personality development. We will explore this idea further in our discussion of psychosexual development, but first, we must identify the parts of the “self” in Freud’s model, or in other words, what constitutes a person’s personality and makes us who we are.

Jean Piaget

Jean Piaget (1896-1980) is considered one of the most influential psychologists of the twentieth century, and his stage theory of cognitive development revolutionized our view of children’s thinking and learning. His work inspired more research than any other theorist, and many of his concepts are still foundational to developmental psychology. His interest lay in children’s knowledge, their thinking, and the qualitative differences in their thinking as it develops. Although he called his field “genetic epistemology,” stressing the role of biological determinism, he also assigned great importance to experience. In his view, children “construct” their knowledge through processes of “assimilation,” in which they evaluate and try to understand new information, based on their existing knowledge of the world, and “accommodation,” in which they expand and modify their cognitive structures based on new experiences.

Modern developmental psychology generally focuses on how and why certain modifications throughout an individual’s life-cycle (cognitive, social, intellectual, personality) and human growth change over time. There are many theorists that have made, and continue to make, a profound contribution to this area of psychology, amongst whom is Erik Erikson who developed a model of eight stages of psychological development. He believed that humans developed in stages throughout their lifetimes and this would affect their behaviors. In this module, we’ll examine some of these major theories and contributions made by prominent psychologists.

Bronfenbrenner’s Ecological Systems Theory

Another psychologist who recognized the importance of the environment on development was American psychologist, Urie Bronfenbrenner (1917-2005), who formulated the ecological systems theory to explain how the inherent qualities of a child and their environment interact to influence how they will grow and develop. The term “ecological” refers to a natural environment; human development is understood through this model as a long-lasting transformation in the way one perceives and deals with the environment. Bronfenbrenner’s ecological theory stresses the importance of studying children in the context of multiple environments because children typically find themselves enmeshed simultaneously in different ecosystems. Each of these systems inevitably interact with and influence each other in every aspect of the child’s life, from the most intimate level to the broadest. Furthermore, he eventually renamed his theory the  bioecological model  in order to recognize the importance of biological processes in development.  However, he only recognized biology as producing a person’s potential, with this potential being realized or not via environmental and social forces.

An individual is impacted by microsystems such as parents or siblings; those who have direct, significant contact with the person. The input of those people is modified by the cognitive and biological state of the individual as well. These influence the person’s actions, which in turn influence systems operating on them. The  mesosystem includes larger organizational structures such as school, the family, or religion. These institutions impact the microsystems just described. For example, the religious teachings and traditions of a family may create a climate that makes the family feel stigmatized and this indirectly impacts the child’s view of themselves and others. The philosophy of the school system, daily routine, assessment methods, and other characteristics can affect the child’s self-image, growth, sense of accomplishment, and schedule, thereby impacting the child physically, cognitively, and emotionally. These mesosystems both influence and are influenced by the larger contexts of the community, referred to as the exosystem . A community’s values, history, and economy can impact the organizational structures it houses. And the community is influenced by macrosystems , which are cultural elements such as global economic conditions, war, technological trends, values, philosophies, and a society’s responses to the global community. In sum, a child’s experiences are shaped by larger forces such as the family, school, religion, and culture. All of this occurs within the relevant historical context and timeframe, or chronosystem .  The chronosystem is made up of the environmental events and transitions that occur throughout a child’s life, including any socio-historical events. This system consists of all the experiences that a person has had during their lifetime.

Comparing and Evaluating Lifespan Theories

Developmental theories provide a set of guiding principles and concepts that describe and explain human development. Some developmental theories focus on the formation of a particular quality, such as Piaget’s theory of cognitive development. Other developmental theories focus on growth that happens throughout the lifespan, such as Erikson’s theory of psychosocial development. It would be natural to wonder which of the perspectives provides the most accurate account of human development, but clearly, each perspective is based on its own premises and focuses on different aspects of development. Many lifespan developmentalists use an eclectic approach, drawing on several perspectives at the same time because the same developmental phenomenon can be looked at from a number of perspectives.

In the table below, we’ll review some of the major theories that you learned about in your introductory course and others that we will cover throughout this text. Recall that three key issues considered in human development examine if development is continuous or discontinuous, if it is the same for everyone or distinct for individuals (one course of development or many), and if development is more influenced by nature or by nurture. The table below reviews how each of these major theories approaches each of these issues.

Periods of Human Development

Think about the lifespan and make a list of what you would consider the basic periods of development. How many periods or stages are on your list? Perhaps you have three: childhood, adulthood, and old age. Or maybe four: infancy, childhood, adolescence, and adulthood. Developmentalists often break the lifespan into nine stages:

• Prenatal Development
• Infancy and Toddlerhood
• Early Childhood
• Middle Childhood
• Adolescence
• Emerging Adulthood
• Early Adulthood
• Middle Adulthood
• Late Adulthood

In addition, the topic of “Death and Dying” is usually addressed after late adulthood since overall, the likelihood of dying increases in later life (though individual and group variations exist). Death and dying will be the topic of our second to last module, though it is not necessarily a stage of development that occurs at a particular age. Our last module will cover grief and bereavement. 

The list of the periods of development reflects unique aspects of the various stages of childhood and adulthood that will be explored in this book, including physical, cognitive, and psychosocial changes. So while both an 8-month-old and an 8-year-old are considered children, they have very different motor abilities, cognitive skills, and social relationships. Their nutritional needs are different, and their primary psychological concerns are also distinctive. The same is true of an 18-year-old and an 80-year-old, both considered adults. We will discover the distinctions between being 28 or 48 as well. But first, here is a brief overview of the stages.

Think about your own development. Which period or stage of development are you in right now? Are you dealing with similar issues and experiencing comparable physical, cognitive, and psychosocial development as described above? If not, why not? Are important aspects of development missing and if so, are they common for most of your cohort or unique to you?

What you’ll learn to do: explain the lifespan perspective

As we have learned, human development refers to the physical, cognitive, and psychosocial changes and constancies in humans over time. There are various theories pertaining to each domain of development, and often theorists and researchers focus their attention on specific periods of development (with most traditionally focusing on infancy and childhood; some on adolescence). But isn’t it possible that development during one period affects development in other periods and that humans can grow and change across adulthood too? In this section, we’ll learn about development through the lifespan perspective, which emphasizes the multidimensional, interconnected, and ever-changing influences on development.

• Describe Baltes’ lifespan perspective with its key principles about development
• Explain what is meant by development being lifelong, multidimensional, and multidirectional
• Explain contextual influences on development

The Lifespan Perspective

Lifespan development involves the exploration of biological, cognitive, and psychosocial changes and constancies that occur throughout the entire course of life. It has been presented as a theoretical perspective, proposing several fundamental, theoretical, and methodological principles about the nature of human development. An attempt by researchers has been made to examine whether research on the nature of development suggests a specific metatheoretical worldview. Several beliefs, taken together, form the “family of perspectives” that contribute to this particular view.

German psychologist Paul Baltes, a leading expert on lifespan development and aging, developed one of the approaches to studying development called the lifespan perspective . This approach is based on several key principles:

• Development occurs across one’s entire life or is lifelong.
• Development is multidimensional,  meaning it involves the dynamic interaction of factors like physical, emotional, and psychosocial development
• Development is multidirectional  and results in gains and losses throughout life
• Development is plastic , meaning that characteristics are malleable or changeable.
• Development is influenced by contextual and socio-cultural influences.
• Development is multidisciplinary.

Development is lifelong

Lifelong development means that development is not completed in infancy or childhood or at any specific age; it encompasses the entire lifespan, from conception to death. The study of development traditionally focused almost exclusively on the changes occurring from conception to adolescence and the gradual decline in old age; it was believed that the five or six decades after adolescence yielded little to no developmental change at all. The current view reflects the possibility that specific changes in development can occur later in life, without having been established at birth. The early events of one’s childhood can be transformed by later events in one’s life. This belief clearly emphasizes that all stages of the lifespan contribute to the regulation of the nature of human development.

Many diverse patterns of change, such as direction, timing, and order, can vary among individuals and affect the ways in which they develop. For example, the developmental timing of events can affect individuals in different ways because of their current level of maturity and understanding. As individuals move through life, they are faced with many challenges, opportunities, and situations that impact their development. Remembering that development is a lifelong process helps us gain a wider perspective on the meaning and impact of each event.

Development is multidimensional

By multidimensionality, Baltes is referring to the fact that a complex interplay of factors influence development across the lifespan, including biological, cognitive, and socioemotional changes. Baltes argues that a dynamic interaction of these factors is what influences an individual’s development.

For example, in adolescence, puberty consists of physiological and physical changes with changes in hormone levels, the development of primary and secondary sex characteristics, alterations in height and weight, and several other bodily changes. But these are not the only types of changes taking place; there are also cognitive changes, including the development of advanced cognitive faculties such as the ability to think abstractly. There are also emotional and social changes involving regulating emotions, interacting with peers, and possibly dating. The fact that the term puberty encompasses such a broad range of domains illustrates the multidimensionality component of development (think back to the physical, cognitive, and psychosocial domains of human development we discussed earlier in this module).

Development is multidirectional

Baltes states that the development of a particular domain does not occur in a strictly linear fashion but that the development of certain traits can be characterized as having the capacity for both an increase and decrease in efficacy over the course of an individual’s life.

If we use the example of puberty again, we can see that certain domains may improve or decline in effectiveness during this time. For example, self-regulation is one domain of puberty that undergoes profound multidirectional changes during the adolescent period. During childhood, individuals have difficulty effectively regulating their actions and impulsive behaviors. Scholars have noted that this lack of effective regulation often results in children engaging in behaviors without fully considering the consequences of their actions. Over the course of puberty, neuronal changes modify this unregulated behavior by increasing the ability to regulate emotions and impulses. Inversely, the ability for adolescents to engage in spontaneous activity and creativity, both domains commonly associated with impulse behavior, decrease over the adolescent period in response to changes in cognition. Neuronal changes to the limbic system and prefrontal cortex of the brain, which begin in puberty lead to the development of self-regulation, and the ability to consider the consequences of one’s actions (though recent brain research reveals that this connection will continue to develop into early adulthood).

Extending on the premise of multidirectionality, Baltes also argued that development is influenced by the “joint expression of features of growth (gain) and decline (loss)”. This relation between developmental gains and losses occurs in a direction to selectively optimize particular capacities. This requires the sacrificing of other functions, a process known as selective optimization with compensation. According to the process of selective optimization, individuals prioritize particular functions above others, reducing the adaptive capacity of particulars for specialization and improved efficacy of other modalities.

The acquisition of effective self-regulation in adolescents illustrates this gain/loss concept. As adolescents gain the ability to effectively regulate their actions, they may be forced to sacrifice other features to selectively optimize their reactions. For example, individuals may sacrifice their capacity to be spontaneous or creative if they are constantly required to make thoughtful decisions and regulate their emotions. Adolescents may also be forced to sacrifice their fast reaction times toward processing stimuli in favor of being able to fully consider the consequences of their actions.

Development is plastic

Plasticity denotes intrapersonal variability and focuses heavily on the potentials and limits of the nature of human development. The notion of plasticity emphasizes that there are many possible developmental outcomes and that the nature of human development is much more open and pluralistic than originally implied by traditional views; there is no single pathway that must be taken in an individual’s development across the lifespan. Plasticity is imperative to current research because the potential for intervention is derived from the notion of plasticity in development. Undesired development or behaviors could potentially be prevented or changed.

As an example, recently researchers have been analyzing how other senses compensate for the loss of vision in blind individuals. Without visual input, blind humans have demonstrated that tactile and auditory functions still fully develop and they can use tactile and auditory cues to perceive the world around them. One experiment designed by Röder and colleagues (1999) compared the auditory localization skills of people who are blind with people who are sighted by having participants locate sounds presented either centrally or peripherally (lateral) to them. Both congenitally blind adults and sighted adults could locate a sound presented in front of them with precision but people who are blind were clearly superior in locating sounds presented laterally. Currently, brain-imaging studies have revealed that the sensory cortices in the brain are reorganized after visual deprivation. These findings suggest that when vision is absent in development, the auditory cortices in the brain recruit areas that are normally devoted to vision, thus becoming further refined.

A significant aspect of the aging process is cognitive decline. The dimensions of cognitive decline are partially reversible, however, because the brain retains the lifelong capacity for plasticity and reorganization of cortical tissue. Mahncke and colleagues developed a brain plasticity-based training program that induced learning in mature adults experiencing an age-related decline. This training program focused intensively on aural language reception accuracy and cognitively demanding exercises that have been proven to partially reverse the age-related losses in memory. It included highly rewarding novel tasks that required attention control and became progressively more difficult to perform. In comparison to the control group, who received no training and showed no significant change in memory function, the experimental training group displayed a marked enhancement in memory that was sustained at the 3-month follow-up period. These findings suggest that cognitive function, particularly memory, can be significantly improved in mature adults with age-related cognitive decline by using brain plasticity-based training methods.

Development is contextual

In Baltes’ theory, the paradigm of contextualism refers to the idea that three systems of biological and environmental influences work together to influence development. Development occurs in context and varies from person to person, depending on factors such as a person’s biology, family, school, church, profession, nationality, and ethnicity. Baltes identified three types of influences that operate throughout the life course: normative age-graded influences, normative history-graded influences, and nonnormative influences. Baltes wrote that these three influences operate throughout the life course, their effects accumulate with time, and, as a dynamic package, they are responsible for how lives develop.

Normative age-graded influences are those biological and environmental factors that have a strong correlation with chronological age, such as puberty or menopause, or age-based social practices such as beginning school or entering retirement. Normative history-graded influences are associated with a specific time period that defines the broader environmental and cultural context in which an individual develops. For example, development and identity are influenced by historical events of the people who experience them, such as the Great Depression, WWII, Vietnam, the Cold War, the War on Terror, or advances in technology.

This has been exemplified in numerous studies, including Nesselroade and Baltes’, showing that the level and direction of change in adolescent personality development was influenced as strongly by the socio-cultural settings at the time (in this case, the Vietnam War) as age-related factors. The study involved individuals of four different adolescent age groups who all showed significant personality development in the same direction (a tendency to occupy themselves with ethical, moral, and political issues rather than cognitive achievement). Similarly, Elder showed that the Great Depression was a setting that significantly affected the development of adolescents and their corresponding adult personalities, by showing a similar common personality development across age groups. Baltes’ theory also states that the historical socio-cultural setting had an effect on the development of an individual’s intelligence. The areas of influence that Baltes thought most important to the development of intelligence were health, education, and work. The first two areas, health and education, significantly affect adolescent development because healthy children who are educated effectively will tend to develop a higher level of intelligence. The environmental factors, health and education, have been suggested by Neiss and Rowe to have as much effect on intelligence as inherited intelligence.

Nonnormative influences are unpredictable and not tied to a certain developmental time in a person’s development or to a historical period. They are the unique experiences of an individual, whether biological or environmental, that shape the development process. These could include milestones like earning a master’s degree or getting a certain job offer or other events like going through a divorce or coping with the death of a child.

The most important aspect of contextualism as a paradigm is that the three systems of influence work together to affect development. Concerning adolescent development, the age-graded influences would help to explain the similarities within a cohort, the history-graded influences would help to explain the differences between cohorts, and the nonnormative influences would explain the idiosyncrasies of each adolescent’s individual development. When all influences are considered together, it provides a broader explanation of an adolescent’s development.

Other Contextual Influences on Development: Cohort, Socioeconomic Status, and Culture

What is meant by the word “context”? It means that we are influenced by when and where we live. Our actions, beliefs, and values are a response to the circumstances surrounding us. Sternberg describes contextual intelligence as the ability to understand what is called for in a situation (Sternberg, 1996). The key here is to understand that behaviors, motivations, emotions, and choices are all part of a bigger picture. Our concerns are such because of who we are socially, where we live, and when we live; they are part of a social climate and set of realities that surround us. Important social factors include cohort, social class, gender, race, ethnicity, and age. Let’s begin by exploring two of these: cohort and social class.  

A  cohort is a group of people who are born at roughly the same time period in a particular society. Cohorts share histories and contexts for living. Members of a cohort have experienced the same historical events and cultural climates which have an impact on the values, priorities, and goals that may guide their lives.

Another context that influences our lives is our social standing, socioeconomic status, or social class. Socioeconomic status is a way to identify families and households based on their shared levels of education, income, and occupation. While there is certainly individual variation, members of a social class tend to share similar lifestyles, patterns of consumption, parenting styles, stressors, religious preferences, and other aspects of daily life.

Culture  is often referred to as a blueprint or guideline shared by a group of people that specifies how to live. It includes ideas about what is right and wrong, what to strive for, what to eat, how to speak, what is valued, as well as what kinds of emotions are called for in certain situations. Culture teaches us how to live in a society and allows us to advance because each new generation can benefit from the solutions found and passed down from previous generations.

Culture is learned from parents, schools, churches, media, friends, and others throughout a lifetime. The kinds of traditions and values that evolve in a particular culture serve to help members function in their own society and to value their own society. We tend to believe that our own culture’s practices and expectations are the right ones. This belief that our own culture is superior is called ethnocentrism and is a normal by-product of growing up in a culture. It becomes a roadblock, however, when it inhibits understanding of cultural practices from other societies. Cultural relativity is an appreciation for cultural differences and the understanding that cultural practices are best understood from the standpoint of that particular culture.

Culture is an extremely important context for human development and understanding development requires being able to identify which features of development are culturally based. This understanding is somewhat new and still being explored. So much of what developmental theorists have described in the past has been culturally bound and difficult to apply to various cultural contexts. For example, Erikson’s  theory that teenagers struggle with identity assumes that all teenagers live in a society in which they have many options and must make an individual choice about their future. In many parts of the world, one’s identity is determined by family status or society’s dictates. In other words, there is no choice to make.

Even the most biological events can be viewed in cultural contexts that are extremely varied. Consider two very different cultural responses to menstruation in young girls. In the United States, girls in public school often receive information on menstruation around 5th grade, get a kit containing feminine hygiene products, and receive some sort of education about sexual health. Contrast this with some developing countries where menstruation is not publicly addressed, or where girls on their period are forced to miss school due to limited access to feminine products or unjust attitudes about menstruation.

Development is Multidisciplinary

Any single discipline’s account of development across the lifespan would not be able to express all aspects of this theoretical framework. That is why it is suggested explicitly by lifespan researchers that a combination of disciplines is necessary to understand development. Psychologists, sociologists, neuroscientists, anthropologists, educators, economists, historians, medical researchers, and others may all be interested and involved in research related to the normative age-graded, normative history-graded, and nonnormative influences that help shape development. Many disciplines are able to contribute important concepts that integrate knowledge, which may ultimately result in the formation of a new and enriched understanding of development across the lifespan.

• Consider your cohort. Can you identify it? Does it have a name and if so, what does the name imply? To what extent does your cohort shape your values, thoughts, and aspirations? (Some cohort labels popularized in the media for generations in the United States include Baby Boomers, Generation X, Millennials, and Generation Z.)
• Think of other ways culture may have affected your development. How might cultural differences influence interactions between teachers and students, nurses and patients, or other relationships?

Additional Supplemental Resources

• Want to participate in a study? Click on a link that sounds interesting to you in order to participate in online research
• U.S. Census Data is available and widely used to look at trends and changes taking place in the United States
• KFF is an endowed, nonprofit organization filling the need for trusted, independent information on national health issues.
• SRCD launched a project to increase the visibility of leading developmental scientists of color who have made critical research contributions and paved the way, through mentoring and advocacy, for younger scholars of color.
• This video gives a summary of Piaget’s theory and his four stages of cognitive development.
• This video summarizes Erikson’s theory of psychosocial development which identifies eight stages in which a healthy individual should pass through from birth to death.
• This video on research methods covers the different categories of psychological research including observational studies and experiments. Closed captioning available.

How to Age Gracefully

• People of all ages offer words of wisdom to their younger counterparts in this WireTap video, from CBC Radio One. It is a great overview of the journey we will take through the lifespan.

Lifespan Development Copyright © 2020 by Julie Lazzara is licensed under a Creative Commons Attribution 4.0 International License , except where otherwise noted.

Share This Book

• school Campus Bookshelves
• menu_book Bookshelves
• perm_media Learning Objects
• login Login
• how_to_reg Request Instructor Account
• hub Instructor Commons
• Download Page (PDF)
• Download Full Book (PDF)
• Periodic Table
• Physics Constants
• Scientific Calculator
• Reference & Cite
• Tools expand_more
• Readability

selected template will load here

This action is not available.

1.1: Introduction to Life Span, Growth and Development

• Last updated
• Save as PDF
• Page ID 2973

• Laura Overstreet
• Western Washington University

Learning Objectives

• Explain the study of human development.
• Define physical, cognitive, and psychosocial development.
• Differentiate periods of human development.
• Analyze your own location in the life span.
• Judge the most and least preferable age groups with which to work.
• Contrast social classes with respect to life chances.
• Explain the meaning of social cohort.
• Critique stage theory models of human development.
• Define culture and ethnocentrism and describe ways that culture impacts development.
• Explain the reasons scientific methods are more objective than personal knowledge.
• Contrast qualitative and quantitative approaches to research.
• Compare research methods noting the advantages and disadvantages of each.
• Differentiate between independent and dependent variables.

Welcome to life span, growth and development. This is the study of how and why people change or remain the same over time.

This course is commonly referred to as the “womb to tomb” course because it is the story of our journeys from conception to death. Human development is the study of how we change over time. Although this course is often offered in psychology, this is a very interdisciplinary course. Psychologists, nutritionists, sociologists, anthropologists, educators, and health care professionals all contribute to our knowledge of the life span.

We will look at how we change physically over time from early development through aging and death. We examine cognitive change, or how our ability to think and remember changes over time. We look at how our concerns and psychological state is influenced by age and finally, how our social relationships change throughout life.

There are several goals of those involved in this discipline:

1. Describing change - many of the studies we will examine simply involve the first step in investigation, which is description. Arnold Gesell’s study on infant motor skills, for example.

2. Explaining changes is another goal. Theories provide explanations for why we change over time. For example, Erikson offers an explanation about why our two-year-old is temperamental.

Think about how you were 5, 10, or even 15 years ago. In what ways have you changed? In what ways have you remained the same? You have probably changed physically; perhaps you’ve grown taller and become heavier. But you may have also experienced changes in the way you think and solve problems. Cognitive change is noticeable when we compare how 6 year olds, 16 year olds, and 46 year olds think and reason, for example. Their thoughts about others and the world are probably quite different. Consider friendship for instance. The 6 year old may think that a friend is someone with whom you can play and have fun. A 16 year old may seek friends who can help them gain status or popularity. And the 46 year old may have acquaintances, but rely more on family members to do things with and confide in. You may have also experienced psychosocial change. This refers emotions and psychological concerns as well as social relationships. Psychologist Erik Erikson suggests that we struggle with issues of independence, trust, and intimacy at various points in our lives. (We will explore this thoroughly throughout the course.)

Our journeys through life are more than biological; they are shaped by culture, history, economic and political realities as much as they are influenced by physical change. This is a very interesting and practical course because it is about us and those with whom we live and work. One of the best ways to gain perspective on our own lives is to compare our experiences with that of others. By periodically making cross-cultural and historical comparisons and by presenting a variety of views on issues such as healthcare, aging, education, gender and family roles, I hope to give you many eyes with which to see your own development. This occurs frequently in the classroom as students from a variety of cultural backgrounds discuss their interpretations of developmental tasks and concerns. I hope to recreate this rich experience as much as possible in this text. So, for example, we will discuss current concerns about the nutrition of children in the United States (for a middle-class boy of 11 years who is 130 pounds overweight and suffering with Pediatric Type II diabetes) as well as malnutrition experienced by children in Ethiopia as a result of drought. Being self-conscious can enhance our ability to think critically about the systems we live in and open our eyes to new courses of action to benefit the quality of life. And knowing about other people and their circumstances can help us live and work with them more effectively. An appreciation of diversity enhances the social skills needed in nursing, education, or any other field.

New Assumptions and Understandings

I took my first graduate course in life span over 20 years ago. Much time was spent on the period of childhood, less on adolescence, and very little attention was given to adulthood. The message was clear: once you are 25, your development is essentially completed. Our academic knowledge of the life span has changed and although there is still less research on adulthood than on childhood, adulthood is gaining increasing attention. This is particularly true now that the large cohort known as the baby boomers are beginning to enter late adulthood. There is so much we need to find out about love, housing, health, nutrition, exercise, social, and emotional development with this large group. (Visit your local bookstore or search the internet and you will find many new titles in the self-help and psychology sections that address this population.)

I was also introduced to the theories of Freud, Erikson, and Piaget, the classic stage theorists whose models depict development as occurring in a series of predictable stages. Stage theories had a certain appeal to an American culture experiencing dramatic change in the early part of the 20th century. But that sense of security was not without its costs; those who did not develop in predictable ways were often thought of as delayed or abnormal. And Freudian interpretations of problems in childhood development, such as autism, held that such difficulties were in response to poor parenting. Imagine the despair experienced by mothers accused of causing their child’s autism by being cold and unloving. It was not until the 1960s that more medical explanations of autism began to replace Freudian assumptions.

Freud and Piaget present a series of stages that essentially end during adolescence. For Freud, we enter the genital stage in which much of our motivation is focused on sex and reproduction and this stage continues through adulthood. Piaget’s fourth stage, formal operational thought, begins in adolescence and continues through adulthood. Again, neither of these theories highlights developmental changes during adulthood. Erikson, however, presents eight developmental stages that encompass the entire lifespan. For that reason, Erikson is known as the “father” of developmental psychology and his psychosocial theory will form the foundation for much of our discussion of psychosocial development.

Today we are more aware of the variations in development and the impact that culture and the environment have on shaping our lives. We no longer assume that those who develop in predictable ways are normal and those who do not are abnormal. And the assumption that early childhood experiences dictate our future is also being called into question. Rather, we have come to appreciate that growth and change continues throughout life and experience continues to have an impact on who we are and how we relate to others. And we recognize that adulthood is a dynamic period of life marked by continued cognitive, social, and psychological development.

Who Studies Human Development?

Many academic disciplines contribute to the study of life span and this course is offered in some schools as psychology; in other schools it is taught under sociology or human development. This multidisciplinary course is made up of contributions from researchers in the areas of health care, anthropology, nutrition, child development, biology, gerontology, psychology, and sociology among others. Consequently, the stories provided are rich and well-rounded and the theories and findings can be part of a collaborative effort to understand human lives.

Many Contexts

People are best understood in context. What is meant by the word “context”? It means that we are influenced by when and where we live and our actions, beliefs, and values are a response to circumstances surrounding us. Sternberg describes a type of intelligence known as “contextual” intelligence as the ability to understand what is called for in a situation (Sternberg, 1996). The key here is to understand that behaviors, motivations, emotions, and choices are all part of a bigger picture. Our concerns are such because of who we are socially, where we live, and when we live; they are part of a social climate and set of realities that surround us. Our social locations include cohort, social class, gender, race, ethnicity, and age. Let’s explore two of these: cohort and social class.

Aries, P. (1962). Centuries of childhood. A social history of family life. New York: Vintage.

Davis, N. (1999). Youth crisis: Growing up in the high risk society. Westport, CN: Praeger.

Debt juggling. The new middle class addiction. (2005, March/April). The Sunday Times Review. Retrieved from www.timesonline.co.uk/article/o..2092-1551813.00.html

DeNavas-Walt, C., & Cleveland, R. W. (2002). Money income in the United States: 2001. Current population reports. (P60-218) (United States, U. S. Census Bureau). U. S. Government Printing Office.

Gilbert, D. (2003). The American class structure in an age of growing inequality. (6th ed.). Belmont, CA: Wadsworth.

Gilbert, D., & Kahl, J. A. (1998). The American class structure. (5th ed.). Belmont, CA: Wadsworth.

Glazer, B. G., & Strauss, A. L. (1967). The discovery of grounded theory: Strategies for qualitative research. New York: Aldine.

Kohn, M. L. (1977). Class and conformity: A study in values. (2nd ed.). Homewood, IL: Dorsey.

Mawathe, A. (2006, March/April). Period misery for Kenya schoolgirls. BBC News. Retrieved August 10, 2006, from http://news.bbc.co.uk/hi/africa/4816558.stm

Seccombe, K., & Warner, R. L. (2004). Marriages and families: Relationships in social context. Belmont, CA: Wadsworth.

Sternberg, R. J. (1996). Sucessful intelligence. New York: Simon and Shuster.

The secret life of the credit card. (2004). PBS: Public Broadcasting Service. Retrieved May 02, 2011, from http://www.pbs.org/cgi-registry/generic/trivia.cgi

Thornton, S. (2005, June/July). Karl Popper (Stanford Encyclopedia of Philosophy/Summer 2005 Edition). Stanford Encyclopedia of Philosophy. Retrieved May 02, 2011, from http://plato.stanford.edu/archives/s...entries/popper

United States, U. S. Census Bureau, Housing and Household Economics Statistics Division. (2005). Poverty Thresholds 2005. Retrieved August 10, 2006, from http://www.census.gov/hhes/www/pover.../thresh05.html

Weitz, R. (2007). The sociology of health, illness, and health care: A critical approach, (4th ed.). Belmont, CA: Thomson.

• Presentations
• Video Clips

The Stages of Life According to Carl Jung

In an essay he wrote in 1931 entitled ”The Stages of Life,” (from ”The Structure and Dynamics of the Psyche,” Volume 8, The Collected Works of Carl Jung ), Jung used the metaphor of the sun sweeping across the horizon to characterize the lifespan. He writes:  “In the morning it rises from the nocturnal sea of unconsciousness and looks upon the wide, bright world which lies before it in an expanse that steadily widens the higher it climbs in the firmament” (p. 397). Beneath the horizon in this model lies the collective unconscious, that universal repository of instinctual images or archetypes that are an integral part of the human psyche, and which are discernible in certain dreams of individuals, and also in important motifs found in world mythology and religion.

Children, in Jung’s view, emerge from this collective unconscious like the rising sun, still having a connection with it during the first few years of life, a phenomenon which can be seen in certain archetypal or Big dreams of young children. Jung emphasized, however, that children need to put this archetypal experience behind them in order to develop their conscious egos so that they can adapt to the world around them.

Jung also observed that children, in their unconscious state, exist in what he called a participation mystique  (a term borrowed from the French anthropologist Lévy-Bruhl) or a state of undifferentiated psychological unity with their parents’ unconscious.  In fact, he often treated the neurotic complaints of his child patients by analyzing the dreams of the parents, and said that much of a child’s early difficulties in adapting to the world was due to the unlived lives of the parents.

Jung believed the awareness of very young children exists only as ”islands” of consciousness in an anarchic or chaotic state.  It then evolves into the development of an ego-complex (which he characterized as a monarchic or monistic stage).  Finally consciousness develops into a divided, or dualistic state (he wrote: ”the inner division with one self, arises when, side by side with the series of ego-contents, a second series of equal intensity comes into being . . we might call it another second ego which can on occasion even wrest the leadership from the first” (p. 391).

According to Jung, consciousness that is fully differentiated from the parents normally takes place only at puberty, with the eruption of sexuality.  He suggested that this important phase of differentiation has been instinctively recognized by indigenous cultures in their development of rites of initiation for young adolescents, which serve to tear them away from their parents both physically and psychologically and introduce them to the spiritual values and adult roles of the culture.

After puberty, the next broad stage that Jung characterized was that of youth (from just after puberty to middle life at thirty-five to forty).  This is a stage that pits the developed ego against the demands of life, which Jung stated can ”harshly put an end to the dream of childhood.”  He notes that “if the individual is sufficiently well prepared, the transition to a profession or career can take place smoothly” (p. 392). But this can also be a difficult time of adaptation if there are ”exaggerated expectations, underestimation of difficulties, unjustified optimism, or a negative attitude” (p. 392). Similarly, disturbances of psychic equilibrium caused by the sexual instinct, or feelings of inferiority, can also make these years of early adulthood highly problematic.

What is often the key difficulty in such situations, according to Jung, is the desire to cling to the earlier stage of childhood.  He writes:  “Something in us wishes to remain a child, to be unconscious or, at most, conscious only of the ego, to reject everything strange, or else subject it to our will, to do nothing, or else indulge our own craving for pleasure or power” (p. 393).

The next important stage or phase, to use Jung’s sun metaphor, is when the sun reaches the high point of its arc across the sky; when it is at ”high noon” or ”mid-life.” Jung is probably the first thinker in the western psychological tradition to discern the existence of a ”mid-life crisis” (decades before Gail Sheehy’s book Passages, turned it into a household term).  Mid-life signals the entrance into what Jung called ”the second half of life.”

Most of his work regarding human development actually focuses on the psychological work to be done during this second half of life. He made a point of emphasizing that the second half of life calls to the fore a different and often compensatory set of values, goals, needs, and priorities from the first half of life. If the first half of life, for example, involved a lot of social striving, professional goals, and focus on self-aggrandizement, then the second half of life should focus more on familial relations, spiritual aspirations, and/or other more humanistic values.  Jung writes:  ”Often it is something like a slow change in a person’s character; in another case, certain traits may come to light which had disappeared since childhood, or again, one’s previous inclinations and interests begin to weaken and others take their place” (p. 395). Compensatory changes also can take place with respect to gender identity, as males develop both physical and psychological traits of the female, while females assume a more masculine inclination and physiognomy.

Then there is the season of life when the sun starts to sink toward the horizon.  Jung devoted a lot of attention, especially in his own later years, to an articulation of the problems and opportunities of old age.  He again was one of the first psychological thinkers to see the positive dimensions of aging, while still acknowledging the presence of debilitation, loss, and discontent. He wrote:  “A human being would certainly not grow to be seventy or eighty years old if this longevity had no meaning for the species.  The afternoon of human life must also have a significance of its own and cannot be merely a pitiful appendage to life’s morning” (p. 399).

In Jung’s later work, he would place a lot of emphasis on the importance of ”individuation” during these later years, where the ego that was so earnestly constructed and held onto in the first half of life, needs to recede in importance, and come into line with one’s larger view of life, incorporating a vital connection with the personal and collective unconscious, a constellation that he termed the Self.  He also recognized the importance of old age to culture, noting how in most cultures old people have always been the guardians of the mysteries and the laws.

Finally, comes death itself, and Jung addressed himself to the attitudes that an older person can attach to his own demise.  He put a lot of emphasis on an individual cultivating an attitude where they actually look ahead to death in a sense, using their religious, spiritual, philosophical, or aesthetic sensibilities to help them cope with this major life experience. Especially for those who have not developed much of themselves (where ”too much unlived life remains”), he suggests that ”it is particularly fatal for such people to look back.” He continues:  ”I am convinced that it is hygienic . . . to discover in death a goal toward which one can strive, and that shrinking away from it is something unhealthy and abnormal which robs the second half of life of its purpose” (p. 402).

This page was brought to you by Thomas Armstrong, Ph.D. and www.institute4learning.com .

Follow me on Twitter:   @Dr_Armstrong

Subscribe to my blog feed

Thomas Armstrong

Related posts, how to become a latebloomer in your fifties or sixties (or later), how our multiple intelligences develop across time, the brain at death and the film mulholland drive.

I visited the Institute for Learning website and was struck by the passion and expertise of its founder, Dr Linda Silverman, and the team of professionals working with her. Their focus on gifted and talented learners is unique and much needed, and their resources and services are invaluable for parents, educators, and anyone interested in fostering exceptional learners’ potential. I also appreciate the focus on the whole child and the importance of understanding each child’s unique learning profile to support their success. Overall, the Institute for Learning is a fantastic resource for anyone who wants to understand better and support gifted learners. Here’s a question that I don’t think is answered on the blog: How can parents and educators identify gifted and talented learners, and what are some common misconceptions or stereotypes about giftedness that should be avoided?

You seem to be talking about a different website. My website focuses on the giftedness in every child. I’ve never believed in singling out one group of children as ”gifted and talented” – since I believe every child is born with a natural zest for learning. What we must do is keep that zest alive – all too often it disappears as the child grows up.

Leave a Reply

Save my name, email, and website in this browser for the next time I comment.

Books by Dr. Armstrong

Follow me on:.

Recent Articles

• Three Seminars Coming up in April
• Leonardo da Vinci’s IEP Meeting (Video)
• Does ADHD Even Exist?
• ADHD Isn’t a Disorder, It’s a Neurodiversity
• 6 Environmental Factors Contributing to ADHD Symptoms

Article Archives

Article categories.

• Adolescence
• Adult Development
• Anxiety Disorders
• Attention Deficit Hyperactivity Disorder (ADHD)
• Audio Books
• Autism Spectrum Disorders
• Awakening Genius
• Book Reviews
• Cross Cultural Issues
• Death and Dying
• Developmental Psychology
• Disappearance of Childhood
• Early Childhood
• Ecology of Learning
• Evolutionary Psychology
• Expressive Arts
• Film Reviews
• Gender Differences
• Genetic Engineering
• Guest Blogs
• Homeschooling
• Human Development
• Human Potential
• Intellectual Disabilities
• Late Adulthood
• Late Childhood
• Learning Disabilties
• Learning Strategies
• Love of Learning
• Media Events
• Middle Childhood
• Midlife Development
• Mindfulness
• Miseducation of America
• Mood Disorders
• Multiple Intelligences
• Neurodiversity
• Neuroscience
• Other Species
• Prebirth and Birth
• Psychotherapy
• Relationships
• Schizophrenia
• School Reforms
• Social Issues
• Speaking Events
• Special Education
• Spirituality
• Stages of Life
• Standardized Testing
• The Power of the Adolescent Brain Video Series
• Trump Watch
• Uncategorized
• Video Series on My Novel Childless
• Video Series on Neurodiversity and Special Education
• Video Series on The Myth of the ADHD Child
• Workplace Issues
• Young Adulthood

Talk to our experts

1800-120-456-456

Human Life Cycle

Various stages of human life.

Human life cycle is the cycle that occurs in human beings and involves a time period for different stages of life. The ideal nutrition and physical well-being ensures prosperity of each stage and helps humans to live more. The major six stages of the human life cycle are known that starts with the prenatal stage where fertilisation takes place and foetal development occurs inside a mother and then ends with the death of human beings. Therefore, old age is the final stage of the life cycle and death is the end of the human life cycle.

Human life cycle biology chapter is there in the books for students and it is easy to understand. In this we’ll talk about the human life cycle and the various stages of the human life cycle. 

What are the Six Stages in the Human Life Cycle?

The Human Life Cycle consists of various stages that include foetus, baby, childhood, adolescence, adulthood and elderly; these are discussed in detail as follows:

Foetus- It is a creation called zygote with the fusion of an egg from the mother and a sperm from the father. Zygote looks like a bundle of cells that divides rapidly and turns into an embryo after about 2-4 weeks inside the mother’s womb. It takes about 8 weeks for the embryo to turn into a human body shape and it is called the foetus.

Baby- After nine months in the mother’s womb, a baby is born. Babies under 1 year of age are called infants and are fed on mother’s milk. Newborn babies are able to suck, breathe, swallow and cry when they feel hungry/cold/hot or any other uncomfortable situation. This is the way of expressing themselves as they cannot talk at this stage.

Childhood- This among the various stages of human life can be divided into 3 sub stages, namely-

Toddler: It is a child who is a grown up baby and is between the ages of 1-3 years. Here, a child slowly learns crawling, walking, talking, running, jumping, identifying things and eating by themselves.

Preschooler: It is a child who is between the ages of 3-5 years. At this sub-stage of childhood, the child can communicate properly, read, write, make friends and indulge in various childhood activities. 

Primary School Kid: It is a child who is between the ages of 5-12 years. At this stage, a child or primary schooler has developed good muscle control and coordination, eye-hand coordination, personal habits, thinking patterns, awareness of safety issues and personal habits and choices.

Adolescence- In this human life cycle stage, a child grows into an adolescent through puberty period. Puberty is the process of physical changes where a child's body matures into an adult body that is capable of sexual reproduction. It starts from the age of 13 years and continues up to 19 years of age. Adolescents are also called teenagers as they belong to thirteen to nineteen years of age range. Many hormonal changes in the body take place that appear externally too. Some of the changes taking place in boys and girls include turning taller, heavier and stronger, getting hair under arms, on arms and legs and around genitals, oily skin and more sweating. Boys' specific changes are deep and rough voice, hair on face, broader chests, shoulders and muscles and girls’ specific changes include development of breasts, bigger hips and start of menstruation cycle. It is considered that the adolescence stage is difficult to manage for parents as there are behavioural and attitudinal changes in teenagers and they find more comfortable in being independent in their day-to-day activities. 

This stage comprises people who fall in the range of ages between 20 -65 years and they are called adults. This is the right age for the process of reproduction and making babies. Adults can be young adults i.e. 20-36 years, middle-aged adults i.e. 36-55 years and older adults i.e. 55-65 years. 

A person who reaches 65 years of age generally belongs to the elderly group. The average life expectancy of a person can range from 70-85 years. It also depends on the overall health and fitness of a person. The healthier a person is, their life expectancy is more. 

So, these were the six different stages of the human life cycle explained above that include fetus (pregnancy), birth of a baby (infant), toddler or preschooler, teenager, adult man/woman and old person.

Characteristic Developmental Features

In all the six stages of the human life cycle, the developmental period shows certain peculiar features of internal growth and external social skills. These are stated below:

The Neonatal stage

In these first few weeks of life, a new born adjusts to the outside world. The head of the neonate is disproportionately larger than the rest of its body. All other body parts are small, soft and tender.

During this short period, the baby spends most of its time asleep., which is broken by short waking periods  (usually every 2-3 hours) on account of any discomfort or for feeding.

They lack neuromuscular control and have underdeveloped organ systems. Their tender bodies and an absolute lack of defense mechanisms make it imperative to closely protect the neonate at this stage.

They are highly vulnerable to diseases and improper nutrition or unhygienic conditions can quickly elevate the susceptibility.

The Infancy period

This is the stage of one of the most rapid periods of growth in the human life cycle.

The metabolic activity increases; there is a higher rate of neuromuscular development. The infant gains some muscle control and shows several body movements such as movement of the eye, swallowing, smiling, moving arms and legs, etc.

It is during this period the child learns to sit and then starts crawling, creeping, standing and finally is able to walk (first with support and then on its own).

They also show psychological development. They can recognise family members and differentiate them from strangers. Withdrawal from strange people, places and things is usually seen.

Finally it gains the concept of “Object permanence” (that is, objects do exist even after they are removed from immediate view sight).

The Childhood period

The childhood years can be further divided into early childhood and late childhood. During this transitional period from infancy, the growth rate slightly slows down. Now the child mainly grows in height and weight relative to each other.

The child shifts from solitary play to parallel play and seeks companionship from children of the same age. They often engage in cooperative play and like to imitate people and their behaviour.

Their vocabulary skills increase and become curious, often asking many questions to their caretakers. They also seek active approval of parents and adults around them

By the age of 9 or 10, girls show rapid growth than boys. In their late childhood, both boys and girls show separate interests which may be common in earlier stages.

The Adolescence

This is again one of the rapid growth periods. They will reach their adult height. Girls often reach their maximum height by their menarche.

Secondary sexual characteristics develop in both boys and girls.

Psychologically, adolescents enter into a period of identity crisis, where they actively seek their purpose in life and develop ideas and beliefs around who they are. They seek individuality as well as approval and being part of a peer group.

There is moral and psychosocial development and proper timely counselling becomes necessary to understand and appreciate their growth.

The adolescent has now transitioned into a full grown adult. There is a marked difference in the understanding of the self and world around them.

They now establish themselves through their careers and relationship with other beings. 

They now seek a marriage partner, build a family and gain status in the society.

Late Adulthood/ Old age (Senescence)

There is loss of several bodily functions gradually

The adult has now retired from its social responsibilities and challenges fully or partially. They however seek delight in helping their children by co-parenting their grandkids.

Sometimes they may feel lonely as children move away for educational and professional reasons. They may find themselves frustrated for being unable to execute many day to day activities without assistance.

Health declines and one may be plagued with many metabolic disorders.

They seek solace in the younger generation or in divine activities (prayers, pilgrimage, etc.).

FAQs on Human Life Cycle

1.  What is Adolescence?

Adolescence is one of the various stages of the human life cycle where a growing child turns to the age of thirteen years and it continues till the age of nineteen years. During this time, a growing child undergoes puberty and develops physical changes such as hair growth, strong muscles, voice cracking, breast development (in girls) and so on.

2. What is Important for Proper Sustenance of the Human Life Cycle?

Personal and community resources are the most important factors that help sustain various stages in the human life cycle. Personal/ Family resources include skills and knowledge, family income, savings and assets, while community resources are the various public institutions (schools, hospitals, parks) and groups set up to create a sense of belonging and overall growth of an individual. They guide, protect and help one flourish when used judiciously.

3. What is the difference between a neonate and an infant?

Both neonates and infants are in their very early stages of human life cycle. However they differ in their developmental stages. A neonate is a newborn who has just begun to adjust in its surroundings. They lack social skills, have difficulty recognising the family members other than the primary caregiver (mother) and spend most of their time asleep. Infants on the other hand are older than neonates and show significant development, especially of the neuromuscular and sensorimotor skills.

4. What are the characteristic features of late adulthood? What is geriatric disease?

The period of late adulthood is primarily characterized by gradual loss of bodily functions. Health is in a constant state of decline and leads to development of one or more nutrient deficiencies. These disorders arising due to old age are known as geriatric disorder. The common geriatric disorders are Type 2 diabetes, high blood pressure, decline in kidney and liver functions (which can lead to partial or complete dependence on dialysis), etc. There may be chewing difficulties, which further disturbs the amount of available nutrition to the body. This can cause unwanted fatigue, loss of focus and a general sense of frustration.

5. What is peer pressure? In what stage of the human life cycle does an individual is under most influence of peer pressure?

Peer pressure is an effect observed in people of the same age group, where they subliminally influence the behaviour and choices of their mates. This is due to an inherent desire to seek approval, be accepted and be seen as a part of the group (of friends, colleagues and coworkers). While peer pressure may be experienced in all stages of life cycle post infancy, its effect is maximum in the adolescent stage, where adolescents have even been known to fall for dangerous behaviors such as rash driving, smoking/ drug addiction, etc., simply to seek approval of their friends.

Biology • Class 10

• Bachelor’s Degrees
• Master’s Degrees
• Doctorate Degrees
• Certificate Programs
• Nursing Degrees
• Cybersecurity
• Human Services
• Science & Mathematics
• Communication
• Liberal Arts
• Social Sciences
• Computer Science
• Admissions Overview
• Tuition and Financial Aid
• Incoming Freshman and Graduate Students
• Transfer Students
• Military Students
• International Students
• Early Access Program
• About Maryville
• Our Faculty
• Our Approach
• Our History
• Accreditation
• Tales of the Brave
• Student Support Overview
• Online Learning Tools
• Infographics

Home / Online Bachelor’s Degree Programs / Online Bachelor’s in Human Development and Family Studies / Bachelor’s in Human Development and Family Studies Resources / Stages of Human Development: What It Is & Why It’s Important

What Is Human Development and Why Is It Important? What Is Human Development and Why Is It Important? What Is Human Development and Why Is It Important?

Take your next brave step.

Receive information about the benefits of our programs, the courses you'll take, and what you need to apply.

Tables of Contents

• Eight Stages of Human Development?
• Theories of Human Development

Human Development vs. Developmental Psychology

What are the genetic factors that affect human growth and development, why do we study human growth and development.

Imagine two children born in the same town and the same year to families with similar socioeconomic statuses. One child grows up to be assertive and confident, while the other grows up to be timid and shy. The study of the stages of human development can help explain the reasons for these differences and much more.

What is human development, exactly? Human development is a branch of psychology with the goal of understanding people — how they develop, grow, and change throughout their lives. This discipline, which can help individuals better understand themselves and their relationships, is broad. As such, it can be used in various professional settings and career paths.

What Are the Eight Stages of Human Development?

If human development is the study of how people change throughout their lives, how and when does this development happen? Many scientists and psychologists have studied various aspects of human development, including ego psychologist Erik Erikson. He examined the impact of social experiences throughout an individual’s life and theorized that  psychosocial development happens in eight sequential parts . What are the eight stages of human development?

Stage 1 — Infancy: Trust vs. Mistrust

In the first stage of human development, infants learn to trust based on how well their caregivers meet their basic needs and respond when they cry. If an infant cries out to be fed, the parent can either meet this need by feeding and comforting the infant or not meet this need by ignoring the infant. When their needs are met, infants learn that relying on others is safe; when their needs go unmet, infants grow up to be less trusting.

Stage 2 — Toddlerhood: Autonomy vs. Shame and Doubt

In addition to autonomy versus shame and doubt, another way to think of the second stage is independence versus dependence. Like in the first stage, toddlers go through this stage responding to their caregivers. If caregivers encourage them to be independent and explore the world on their own, toddlers will grow up with a sense of self-efficacy. If the caregivers hover excessively or encourage dependence, these toddlers grow up with less confidence in their abilities.

For example, if a toddler wants to walk without assistance in a safe area, the caregiver should encourage this autonomy by allowing the independent behavior. If the caregiver insists on holding the toddler’s hand even when it’s not necessary, this attention can lead to doubt later in life.

Stage 3 — Preschool Years: Initiative vs. Guilt

During the preschool years, children learn to assert themselves and speak up when they need something. Some children may state that they’re sad because a friend stole their toy. If this assertiveness is greeted with a positive reaction, they learn that taking initiative is helpful behavior. However, if they’re made to feel guilty or ashamed for their assertiveness, they may grow up to be timid and less likely to take the lead.

Stage 4 — Early School Years: Industry vs. Inferiority

When children begin school, they start to compare themselves with peers. If children feel they’re accomplished in relation to peers, they develop strong self-esteem. If, however, they notice that other children have met milestones that they haven’t, they may struggle with self-esteem. For example, a first grader may notice a consistently worse performance on spelling tests when compared with peers. If this becomes a pattern, it can lead to feelings of inferiority.

The key components of Erikson’s model of human development include stage one, infancy, trust versus mistrust; stage two, toddlerhood, autonomy versus shame and doubt; stage three, preschool years, initiative versus guilt; stage four, early school years, industry versus inferiority; stage five, adolescence, identity versus role confusion; stage six, young adulthood, intimacy versus isolation; stage seven, middle adulthood, generativity versus stagnation; and stage eight, late adulthood, integrity versus despair.

Back To Top

Stage 5 — Adolescence: Identity vs. Role Confusion

The adolescent stage is where the term “identity crisis” originated, and for good reason. Adolescence is all about developing a sense of self. Adolescents who can clearly identify who they are grow up with stronger goals and self-knowledge than teenagers who struggle to break free of their parents’ or friends’ influences. Adolescents who still deeply depend on their parents for social interaction and guidance may experience more role confusion than teenagers who pursue their own interests.

Stage 6 — Young Adulthood: Intimacy vs. Isolation

In young adulthood, which begins roughly at age 20, people begin to solidify their lifelong bonds; many people enter committed relationships or marriages, while others form lifelong friendships. People who can create and maintain these relationships reap the emotional benefits, while those who struggle to maintain relationships may suffer from isolation. A young adult who develops strong friendships in college may feel more intimacy than one who struggles to form and maintain close friendships.

Stage 7 — Middle Adulthood: Generativity vs. Stagnation

In middle adulthood, people tend to struggle with their contributions to society. They may be busy raising children or pursuing careers. Those who feel that they’re contributing experience generativity, which is the sense of leaving a legacy. On the other hand, those who don’t feel that their work or lives matter may experience feelings of stagnation. For example, a middle-aged adult who’s raising a family and working in a career that presumably helps people may feel more fulfilled than an adult who’s working at a day job that feels meaningless.

Stage 8 — Late Adulthood: Integrity vs. Despair

As adults reach the end of life, they look back on their lives and reflect. Adults who feel fulfilled by their lives, either through a successful family or a meaningful career, reach ego integrity, in which they can face aging and dying with peace. If older adults don’t feel that they’ve lived a good life, they risk falling into despair.

Other Theories of Human Development

Although widely used, Erikson’s psychosocial development theory has been critiqued for focusing too much on childhood. Critics claim that his emphasis makes the model less representative of the growth that people experienced in adulthood. Erikson’s model of the stages of human development is only one theory addressing growth and change throughout life, as many other psychologists have researched their own  theories of human development , including the following:

Cognitive Development

Jean Piaget developed the theory of cognitive development. Piaget’s theory is widely used in education programs to prepare teachers to instruct students in developmentally appropriate ways. The theory is based on four stages:

• Sensorimotor —  In the sensorimotor stage (birth to 2 years old), children learn object permanence, which is the understanding that people and objects still exist even when they’re out of view.
• Preoperational —  In the preoperational stage (2-7 years old), children develop symbolic thought, which is when they begin to progress from concrete to abstract thinking. Children in this stage often have imaginary friends.
• Concrete operational —  In the concrete operational stage (7-11 years old), children solidify their abstract thinking and begin to understand cause and effect and logical implications of actions.
• Formal operational —  In the formal operational stage (adolescence to adulthood), humans plan for the future, think hypothetically, and assume adult responsibilities.

Moral Development

Lawrence Kohlberg created a theory of human development based on moral development concepts. The theory comprises the following stages:

• Preconventional —  In the preconventional stage, people follow rules because they’re afraid of punishment and make choices only with their best interests in mind.
• Conventional —  In the conventional stage, people act to avoid society’s judgment and follow rules to maintain the systems and structures that are already in place.
• Postconventional —  In the postconventional stage, a genuine concern for the welfare of others and the greater good of society guides people.

Psychosexual Theory

Sigmund Freud popularized the  psychosexual theory . The theory comprises five stages:

• Oral —  In the oral stage (birth to 1 year old), children learn to suck and swallow and may experience conflict with weaning.
• Anal —  In the anal stage (1-3 years old), children learn to withhold or expel feces and may experience conflict with potty training.
• Phallic —  In the phallic stage (3-6 years old), children discover that their genitals can give them pleasure.
•   Latency —  In the latency stage (roughly 6 years old through puberty), they take a break from these physical stages and instead develop mentally and emotionally.
• Genital —  In the genital stage (puberty through adulthood), people learn to express themselves sexually.

Ideally, children move through each phase fluidly as their sexual libidos develop, but if they’re stuck in any of the phases, they may develop a fixation that hinders their development.

Behavioral Theory

The behavioral theory focuses solely on a person’s behaviors rather than the feelings that go alongside those behaviors. It suggests that behaviors are conditioned in an environment due to certain stimuli. Behavioral theorists believe that behavior determines feelings, so changing behaviors is important because this will in turn change feelings.

The  attachment theory  focuses on the deep relationships between people across their lifetime. An important attachment theory finding is that children must develop at least one strong bond in childhood to trust and develop relationships as adults. The attachment theory comprises four stages:

• Asocial or  pre-attachment   (birth to 6 weeks old)
• Indiscriminate attachment (6 weeks old to 7 months old)
• Specific or discriminate attachment (7-9 months old)
• Multiple attachments (10 months old or later)

Social Learning Theory

The social learning theory builds upon the behavioral theory and postulates that people learn best by observing the behavior of others. They watch how others act, view the consequences, and then make decisions regarding their own behavior accordingly. The four stages in this theory are:

• Reproduction

In the attention stage, people first notice the behavior of others. In the retention stage, they remember the behavior and the resulting consequences. In the reproduction stage, people develop the ability to imitate the behaviors they want to reproduce, and in the motivation stage, they perform these behaviors.

Sociocultural Theory

The  sociocultural theory  ties human development to the society or culture in which people live. It focuses on the contributions that society as a whole makes to individual human development. For example, children who are raised to play outdoors develop differently from children who are raised to play indoors.

An important part of this theory is the zone of proximal development, which is an area of knowledge and skills slightly more advanced than a child’s current level. The zone of proximal development helps teachers think about and plan instruction, so sociocultural theory plays a large role in preservice teacher training.

Resources: More Information on Theories of Human Development

• BetterHelp, “Behavioral Theory, Behavioral Psychology, or Behaviorism? How Behavior and Personality Intersect ”
• Encyclopedia Britannica, “Lawrence Kohlberg’s Stages of Moral Development”
• Healthline, “What Are Freud’s Psychosexual Stages of Development?”
• PositivePsychology.com, “What Is Attachment Theory? Bowlby’s 4 Stages Explained”
• Psychology Today , Social Learning Theory
• SimplyPsychology, “Lev Vygotsky’s Sociocultural Theory”
• SimplyPsychology, Theories of Psychology
• Verywell Mind, “The 4 Stages of Cognitive Development”

What are the differences between human development and developmental psychology? These terms are closely related. In fact, the study of developmental psychology is most people’s entry into human development.

Developmental psychology  is defined as a scientific approach to explaining growth, change, and consistency throughout a lifetime. It uses various frameworks to understand how people develop and transform throughout their lives. The goals of developmental psychology are to describe, explain, and optimize development to improve people’s lives. In the real world, developmental psychology is used in the study of physical, psychological, emotional, social, personality, and perceptual development.

The  study of developmental psychology  can lead to careers in several different fields. Developmental psychologists often work in colleges and universities and focus on research and teaching. Others work in healthcare facilities, clinics, assisted living facilities, hospitals, mental health clinics, or homeless shelters. In these applied settings, their focus is more on assessing, evaluating, and treating people. According to June 2020 data from PayScale, developmental  psychologists earn an average annual salary of about $68,000 .

One more key element of human growth and development left to explore is  genetics . Genetics influences the speed and way in which people develop, though other factors, such as parenting, education, experiences, and socioeconomic factors, are also at play. The multiple genetic factors that affect human growth and development include genetic interactions and sex chromosome abnormalities.

Genetic Interactions

Genes can act in an additive way or sometimes conflict with one another. For example, a child with one tall parent and one short parent may end up between the two of them, at average height. Other times, genes follow a dominant-recessive pattern. If one parent has brown hair and the other has red hair, the red hair gene is the dominant gene if their child has red hair.

Gene-Environment Interactions

Humans’ genetic information is always interacting with the environment, and sometimes this can impact development and growth. For example, if a child in utero is exposed to drugs, the child’s cognitive abilities may be impacted, thus changing the developmental process. In addition, even if a child’s genes would indicate a tall height, if that child experiences poor nutrition as children, it may impact their height.

Sex Chromosome Abnormalities

Sex chromosome abnormalities impact as many as 1 in 500 births. The following syndromes are examples of sex chromosome abnormalities that can impact development:

• Klinefelter syndrome  is the presence of an extra X chromosome in males, which can cause physical characteristics such as decreased muscle mass and reduced body hair and may cause learning disabilities.
• Fragile X syndrome  is caused by a mutation in the FMR1 gene that makes the X chromosome  appear fragile . It can cause intellectual disability, developmental delays, or distinctive physical features such as a long face.
• Turner syndrome  happens when one of the X chromosomes is missing or partially missing. It only affects females and results in physical characteristics like short stature and webbed neck.

Down Syndrome

Down syndrome  is another common example of how genetics can impact development. This chromosomal disorder may cause some individuals to experience physical or intellectual development differences. Down syndrome occurs at the 21st chromosomal site, in which people with Down syndrome have three chromosomes rather than two.

Those with Down syndrome often have different physical characteristics and may be prone to physical problems like heart defects and hearing problems. Most individuals with Down syndrome have intellectual impairment, but the degree of this impairment varies from person to person.

The top reasons for studying human development are to gain an understanding of your own life experience, help others understand what they’re going through, understand the relationship of society and individual growth, lead more effectively, and support the physical and mental health of others.

The study of human growth and development offers a wealth of value for personal and professional growth and understanding. Many reasons exist for why we study human growth and development.

Common benefits include the following:

• To  gain a better understanding  of one’s own life experiences. This can help people personally reach an understanding of what childhood events shaped their adulthood.
• To  gain knowledge  of how social context impacts development. This knowledge can be invaluable for professionals like teachers as they gain a deeper understanding of their students.
• To  help others understand and contextualize  the ups and downs of life. This helps therapists and psychologists better aid their clients in self-discovery.
• To  understand how societal change can support growth  and development. This understanding helps decision-makers in schools change the educational culture for the better.
• To  become a more effective research, teacher, or leader  in many different industries. Understanding human development deeply and in context has many professional benefits that can lead to greater insight.
• To  support the physical and mental health of individuals  throughout their life span. Professionals like doctors, nurses, and therapists must understand human growth and development to better support their clients.

Students may choose to study human growth and development because of its array of applications across many professional fields. For example, students who want to become elementary school teachers may take courses on the stages of human development to understand cognitive development and how children’s brains grow and change.

Human development is a wide-reaching and ever-changing discipline. A knowledge of human development can be invaluable to people personally as they continue to learn and grow throughout their lives and professionally as they learn to apply what they’ve learned to their careers.

Infographic Sources

Financial Express, “The Eight Stages of Human Development”

VeryWell Mind, “5 Reasons to Study Human Development”

Bring us your ambition and we’ll guide you along a personalized path to a quality education that’s designed to change your life.

Life’s stages are changing – we need new terms and new ideas to describe how adults develop and grow

Senior Research Scholar, Department of Psychology, Clark University

Disclosure statement

Jeffrey Arnett does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

View all partners

What image comes to mind when you think of a person in their 20s?

Do you imagine an adult stressed out by the weight of many new responsibilities in family and work roles?

Or do you envision someone who is bursting with hope and undeveloped potential, still more of a kid than an adult, struggling to define a life and making little or no money but managing to find occasional joy nevertheless? Perhaps your soundtrack here is Taylor Swift’s radiant “22” : “We’re happy, free, confused and lonely at the same time. It’s miserable and magical.”

How about when you think of someone in their 60s?

Do you envision someone – or maybe a happy couple – enjoying life, living well, still vigorous but now freer than before from daily work and family duties?

Or do you see someone who is stooped over from a lifetime of carrying burdens, their health diminished, now shuffling toward no particular destination? Here the soundtrack might be the doleful Beatles song “ When I’m 64 ”: “Will you still need me? Will you still feed me? When I’m 64?”

The whole arc of adult development has changed over the past several decades, in ways that our psychological theories are still catching up with. In the 21st century, does it still make sense to refer to “young adulthood,” “midlife” and “late adulthood,” as psychologists have been doing for so long? If not, what are more accurate concepts?

Most of my career as a developmental psychologist has been devoted to answering these questions. My theory of emerging adulthood recognizes that the lives of younger adults have changed vastly since the 1960s. As the father of 22-year-old twins, I’m keenly aware of their journey through the new life stage I have been researching and writing about for so long. As a 64-year-old, I’m also turning my attention to how the 60s have changed from what they used to be.

A longer-than-ever journey to adulthood

In my research over the past two decades, I’ve found that people ages 19 to 29 are neither fully adult nor in an “extended adolescence” – as this time of life was viewed over the course of the 20th century. In the early 21st century, these years had become a time of gradually and often erratically making one’s way toward a more established adulthood .

I invited scholars from all over the world to contribute to a special issue of American Psychologist, one of the top journals in psychology, on the theme of “Rethinking Adult Development: New Ideas for New Times.” The recently published results are a wonderfully diverse set of papers that go a long way toward reconceptualizing what adult development looks like now and where it might be going.

Most of the authors were developmental psychologists. About half were Americans and half were Europeans, although Shinobu Kitayama and his colleagues offered a refreshingly different Asian cultural perspective.

Here are some of the highlights:

– Ages 30 to 45 are now “the rush hour of life.” Today people around the world wait later than ever to marry and have kids, and most have only one or two. But then couples typically have the dual challenge of trying to move ahead in their careers while also handling the intense responsibilities of caring for young children. Women have vastly greater opportunities in education and work than they did in 1960, which is welcome but also presents new challenges and stresses.

In their contribution to the special issue, Clare Mehta and her colleagues propose the term “established adulthood” to distinguish these years as the most intense and demanding years of adult life, characterized by the “career-and-care-crunch,” when obligations are high in both work and family roles.

– In midlife – ages 45-60 – the crunch years of caring for young children abate. Adults reach their peak career earnings and status in their late 40s and 50s. But life can become complicated, as new responsibilities may arise with grandchildren and with aging parents who need more assistance.

Overall, as Frank Infurna and colleagues detail in their contribution, mental health declines in midlife. Reports of depression and anxiety increase. Seeking professional help for mental health issues reaches a lifetime peak.

Furthermore, midlife well-being, health and life expectancy have declined notably in the U.S. since 2000, especially among working-class adults who have been left behind by the information-and-technology economy. This has led to an epidemic of “deaths of despair” from suicide, opioid overdoses or alchoholism.

– Adults in later life, ages 60-75, are thriving like never before. Although life after age 60 is traditionally regarded as a time of inevitable decline, the reality of it has become sharply different –and better – in recent decades.

Life expectancy at birth is higher now than it has ever been, worldwide, and adults are smarter and healthier for longer than ever. Denis Gerstorf and his colleagues show how these positive trends have taken place across many countries over the past century because of improvements in education, nutrition and health care.

[ Like what you’ve read? Want more? Sign up for The Conversation’s daily newsletter .]

Physical health issues do arise with age for most people, but more people than ever before stay healthy through their 60s and early 70s by maintaining healthy diet and physical exercise practices. One of the exciting recent findings highlighted in Ursula Staudinger’s article is that regular exercise promotes mental health as well as physical well-being, helping to maintain mental sharpness and prevent Alzheimer’s disease.

Life satisfaction also seems to rise in later life, as we gain a new freedom to choose the kind of work we do – or stop working altogether and spend more time with the people we care about most. According to Phillip Ackerman and Ruth Kanfer , more people are working into their late 60s and early 70s than ever before, but they have more freedom to choose how they do it, whether it’s working part time, starting a small business or trying something they have always wanted to do.

Adulthood’s new arc requires new concepts and ideas

Over my decades of writing about emerging adulthood, I’ve learned that it matters how people think about the stages of human development. Thinking shapes expectations and how experiences are interpreted. Lots of compelling and exciting new findings about adult development point to the importance of rethinking previous theories, assumptions and stereotypes about the course of adult life.

• Early adulthood
• early career
• Cultural change

Deputy Social Media Producer

Research Fellow /Senior Research Fellow – Implementation Science

Associate Professor, Occupational Therapy

GRAINS RESEARCH AND DEVELOPMENT CORPORATION CHAIRPERSON

Faculty of Law - Academic Appointment Opportunities

The Life Span Perspective of Development Essay

The aspects of the life span perspective of development, freud and erickson’s theories of life span development, interaction of the heredity and environment.

During the life, people change significantly with references to their physical appearance and characteristics and with references to their mental and emotional progress. The life span perspective of the human development is based on the idea that a person moves through several stages of development during the whole life (Berger, 2011, p. 7).

Thus, certain changes are typical for the definite stages of life, but it is also important to pay attention to the individual character of experienced changes because all the people are different. From this point, the life span perspective aims to explain the human development with the focus on separate phases completed during the whole life; and all the stages of the human development are taken into consideration in spite of the fact that the followers of this perspective are inclined to determine phases according to different criteria.

The life span perspective of the human development is characterized by the complex approach to analyzing all the aspects of the people’s changes observed during different life stages. As a result, it is possible to speak about the multidimensional character of the approach because all the aspects are discussed in their connection.

According to Berger, the human development presented as the life span is multidirectional, multicontextual, multicultural, multidisciplinary, and plastic (Berger, 2011, p. 10-18). This statement means that it is irrelevant to discuss the human development as started at one point and moving to another one; or as dependent only on one context, including only the family or social status; or as dependent only on one culture.

The people’s development is the complex process because a person is influenced by a lot of environments, cultures, and situations during the life span. This person interacts with many people belonging to different cultures and ethnic groups and develops the specific personal traits during the whole life (Berger, 2011, p. 10). Each detail associated with the person’s life, such as the family, socioeconomic status, and character, matters to explain the aspects of the person’s life span development.

There are many theories of the life span development which differ in criteria according to which psychologists determine different stages of the people’s life. Freud and Erickson’s theories are similar in focusing on the age-related steps, but they are different in criteria to state the fundaments for the stages’ progress. Thus, Freud’s theory depends on a range of psychosexual phases because the theorist is inclined to associate the man’s sexual nature with the psychological development.

Freud concentrates on the childhood as the period when a child experiences some crises which determine the oral, anal, phallic phases, and the period of latency. These periods lead to the genital stage lasting during the adolescence and adulthood. According to Freud, the stages depend on the centers of pleasures important during different stages (Berger, 2011, p. 43-47). As a result, the human sexual nature is chosen as the criterion to propose the life span stages.

Erickson’s theory is based on the social aspect. If Freud’s theory depends on psychological crises associated with the sexual development, Erickson’s theory depends on psychological crises associated with the people’s social interactions. Erickson states that people move through a range of stages during which they are impacted by the peculiarities of the environments and interactions with people.

People’s activities and behaviors during different stages are explained with references to their attitude to their society and personal interactions. As a result, at different stages, people are influenced by the conflicts between their identity or independent life and society which can be represented as the family, relatives, friends, and other people (Berger, 2011, p. 51).

A person can be discussed as an individual only with references to the unique combination of the heredity and environment’s impact on his or her development. Today, scientists cannot provide the single opinion on the role of nature and nurture in the person’s development because it is impossible to state what factors affect the personal development drastically. Heredity makes people different in their appearance and physical qualities when nurture makes people different in their vision of the world, education, and lifestyle.

It is important to note that nature and nurture are in ongoing interaction to affect the person’s individual development. The unique complex of the genetic material and environment produces a unique person who should be discussed only with references to combination of heredity and environment (Berger, 2011, p. 9). Inherited qualities should be combined with the environment’s impact to influence the individual’s development.

The life span perspective of the human development depends on the idea that people move through many stages during their life, but this movement should be discussed as the multidimensional process rather than as the linear movement. Such aspects as the interaction of nurture and nature can influence the person’s development significantly because various inherited qualities or life situations can affect the people’s life differently.

Berger, K. S. (2011). The developing person through the life span . New York, NY: Worth Publishers.

• Chicago (A-D)
• Chicago (N-B)

IvyPanda. (2019, November 23). The Life Span Perspective of Development. https://ivypanda.com/essays/the-life-span-perspective-of-development/

"The Life Span Perspective of Development." IvyPanda , 23 Nov. 2019, ivypanda.com/essays/the-life-span-perspective-of-development/.

IvyPanda . (2019) 'The Life Span Perspective of Development'. 23 November.

IvyPanda . 2019. "The Life Span Perspective of Development." November 23, 2019. https://ivypanda.com/essays/the-life-span-perspective-of-development/.

1. IvyPanda . "The Life Span Perspective of Development." November 23, 2019. https://ivypanda.com/essays/the-life-span-perspective-of-development/.

Bibliography

IvyPanda . "The Life Span Perspective of Development." November 23, 2019. https://ivypanda.com/essays/the-life-span-perspective-of-development/.

• Piaget and Erickson’s Developmental Stages
• Erik Erickson. Trust versus Mistrust
• Erickson's Theory of Development
• Erickson’s Model of Development of Person
• Erickson’s Theory of Psychosocial Development
• “Death of a Salesman” by Steven Erickson
• Eric Erickson's Theory Explaining Development
• Clif Bar Inc. Balancing Priorities
• Chapter 2 of Essentials of Life-Span Development by Santrock
• Behavioral Science: Heredity and Hormones
• Concept Of “Four Idols”
• How ADHD Develops Into Adult ADD
• The Effect of Emotions and Desires on Individual Development
• Workplace Motivation Theories
• Psychosocial Theory of Development by Erick Erikson

• Bipolar Disorder
• Therapy Center
• When To See a Therapist
• Types of Therapy
• Best Online Therapy
• Best Couples Therapy
• Best Family Therapy
• Managing Stress
• Sleep and Dreaming
• Understanding Emotions
• Self-Improvement
• Healthy Relationships
• Student Resources
• Personality Types
• Guided Meditations
• Verywell Mind Insights
• 2023 Verywell Mind 25
• Mental Health in the Classroom
• Editorial Process
• Meet Our Review Board
• Crisis Support
• Trust vs. Mistrust
• Autonomy vs. Shame and Doubt
• Initiative vs. Guilt
• Industry vs. Inferiority
• Identity vs. Confusion
• Intimacy vs. Isolation
• Generativity vs. Stagnation
• Integrity vs. Despair

Erikson's Stages of Development

A Closer Look at the Eight Psychosocial Stages

Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."

• Overview of Erikson's Stages of Development
• Support and Criticism
• Next in Psychosocial Development Guide Trust vs. Mistrust: Psychosocial Stage 1

Erik Erikson was an ego psychologist who developed one of the most popular and influential theories of development. While his theory was impacted by psychoanalyst Sigmund Freud's work , Erikson's theory centered on psychosocial development rather than psychosexual development .

The stages that make up his theory are as follows:

• Stage 1 : Trust vs. Mistrust (Infancy from birth to 18 months)
• Stage 2 : Autonomy vs. Shame and Doubt (Toddler years from 18 months to three years)
• Stage 3 : Initiative vs. Guilt (Preschool years from three to five)
• Stage 4 : Industry vs. Inferiority (Middle school years from six to 11)
• Stage 5 : Identity vs. Confusion (Teen years from 12 to 18)
• Stage 6 : Intimacy vs. Isolation (Young adult years from 18 to 40)
• Stage 7 : Generativity vs. Stagnation (Middle age from 40 to 65)
• Stage 8 : Integrity vs. Despair (Older adulthood from 65 to death)

Let's take a closer look at the background and different stages that make up Erikson's psychosocial theory.

Overview of Erikson's Stages of Development

So what exactly did Erikson's theory of psychosocial development entail? Much like Sigmund Freud , Erikson believed that personality developed in a series of stages.

Unlike Freud's theory of psychosexual stages, however, Erikson's theory described the impact of social experience across the whole lifespan. Erikson was interested in how social interaction and relationships played a role in the development and growth of human beings.

Erikson's theory was based on what is known as the epigenetic principle . This principle suggests that people grow in a sequence that occurs over time and in the context of a larger community.

Click Play to Learn More About Erik Erikson’s Stages of Psychosocial Development

This video has been medically reviewed by Steven Gans, MD .

Conflict During Each Stage

Each stage in Erikson's theory builds on the preceding stages and paves the way for following periods of development. In each stage, Erikson believed people experience a conflict that serves as a turning point in development.  

In Erikson's view, these conflicts are centered on either developing a psychological quality or failing to develop that quality. During these times, the potential for personal growth is high but so is the potential for failure.

If people successfully deal with the conflict, they emerge from the stage with psychological strengths that will serve them well for the rest of their lives. If they fail to deal effectively with these conflicts, they may not develop the essential skills needed for a strong sense of self.

Mastery Leads to Ego Strength

Erikson also believed that a sense of competence motivates behaviors and actions. Each stage in Erikson's theory is concerned with becoming competent in an area of life.

If the stage is handled well, the person will feel a sense of mastery, which is sometimes referred to as ego strength or ego quality. If the stage is managed poorly, the person will emerge with a sense of inadequacy in that aspect of development.

Stage 1: Trust vs. Mistrust

The first stage of Erikson's theory of psychosocial development occurs between birth and 1 year of age and is the most fundamental stage in life. Because an infant is utterly dependent, developing trust is based on the dependability and quality of the child's caregivers.

At this point in development, the child is utterly dependent upon adult caregivers for everything they need to survive including food, love, warmth, safety, and nurturing. If a caregiver fails to provide adequate care and love, the child will come to feel that they cannot trust or depend upon the adults in their life.

If a child successfully develops trust, the child will feel safe and secure in the world.   Caregivers who are inconsistent, emotionally unavailable, or rejecting contribute to feelings of mistrust in the children under their care. Failure to develop trust will result in fear and a belief that the world is inconsistent and unpredictable.

During the first stage of psychosocial development, children develop a sense of trust when caregivers provide reliability, care, and affection. A lack of this will lead to mistrust.

No child is going to develop a sense of 100% trust or 100% doubt. Erikson believed that successful development was all about striking a balance between the two opposing sides. When this happens, children acquire hope, which Erikson described as an openness to experience tempered by some wariness that danger may be present.

Subsequent work by researchers including John Bowlby and Mary Ainsworth demonstrated the importance of trust in forming healthy attachments during childhood and adulthood.

Stage 2: Autonomy vs. Shame and Doubt

The second stage of Erikson's theory of psychosocial development takes place during early childhood and is focused on children developing a greater sense of personal control.

The Role of Independence

At this point in development, children are just starting to gain a little independence. They are starting to perform basic actions on their own and making simple decisions about what they prefer. By allowing kids to make choices and gain control, parents and caregivers can help children develop a sense of autonomy.  

Potty Training

The essential theme of this stage is that children need to develop a sense of personal control over physical skills and a sense of independence. Potty training plays an important role in helping children develop this sense of autonomy.

Like Freud, Erikson believed that toilet training was a vital part of this process. However, Erikson's reasoning was quite different than that of Freud's. Erikson believed that learning to control one's bodily functions leads to a feeling of control and a sense of independence. Other important events include gaining more control over food choices, toy preferences, and clothing selection.

Children who struggle and who are shamed for their accidents may be left without a sense of personal control. Success during this stage of psychosocial development leads to feelings of autonomy; failure results in feelings of shame and doubt.

Finding Balance

Children who successfully complete this stage feel secure and confident, while those who do not are left with a sense of inadequacy and self-doubt. Erikson believed that achieving a balance between autonomy and shame and doubt would lead to will, which is the belief that children can act with intention, within reason and limits.

Stage 3: Initiative vs. Guilt

The third stage of psychosocial development takes place during the preschool years. At this point in psychosocial development, children begin to assert their power and control over the world through directing play and other social interactions.

Children who are successful at this stage feel capable and able to lead others. Those who fail to acquire these skills are left with a sense of guilt, self-doubt, and lack of initiative.

The major theme of the third stage of psychosocial development is that children need to begin asserting control and power over the environment. Success in this stage leads to a sense of purpose. Children who try to exert too much power experience disapproval, resulting in a sense of guilt.

When an ideal balance of individual initiative and a willingness to work with others is achieved, the ego quality known as   purpose emerges.

Stage 4: Industry vs. Inferiority

The fourth psychosocial stage takes place during the early school years from approximately ages 5 to 11. Through social interactions, children begin to develop a sense of pride in their accomplishments and abilities.

Children need to cope with new social and academic demands. Success leads to a sense of competence, while failure results in feelings of inferiority.

Children who are encouraged and commended by parents and teachers develop a feeling of competence and belief in their skills. Those who receive little or no encouragement from parents, teachers, or peers will doubt their abilities to be successful.

Successfully finding a balance at this stage of psychosocial development leads to the strength known as competence, in which children develop a belief in their abilities to handle the tasks set before them.

Stage 5: Identity vs. Confusion

The fifth psychosocial stage takes place during the often turbulent teenage years. This stage plays an essential role in developing a sense of personal identity which will continue to influence behavior and development for the rest of a person's life. Teens need to develop a sense of self and personal identity. Success leads to an ability to stay true to yourself, while failure leads to role confusion and a weak sense of self.

During adolescence, children explore their independence and develop a sense of self.   Those who receive proper encouragement and reinforcement through personal exploration will emerge from this stage with a strong sense of self and feelings of independence and control. Those who remain unsure of their beliefs and desires will feel insecure and confused about themselves and the future.

What Is Identity?

When psychologists talk about identity, they are referring to all of the beliefs, ideals, and values that help shape and guide a person's behavior. Completing this stage successfully leads to fidelity, which Erikson described as an ability to live by society's standards and expectations.

While Erikson believed that each stage of psychosocial development was important, he placed a particular emphasis on the development of ego identity. Ego identity is the  conscious  sense of self that we develop through social interaction and becomes a central focus during the identity versus confusion stage of psychosocial development.

According to Erikson, our ego identity constantly changes due to new experiences and information we acquire in our daily interactions with others. As we have new experiences, we also take on challenges that can help or hinder the development of identity.

Why Identity Is Important

Our personal identity gives each of us an integrated and cohesive sense of self that endures through our lives. Our sense of personal identity is shaped by our experiences and interactions with others, and it is this identity that helps guide our actions, beliefs, and behaviors as we age.

Stage 6: Intimacy vs. Isolation

Young adults need to form intimate, loving relationships with other people. Success leads to strong relationships, while failure results in loneliness and isolation. This stage covers the period of early adulthood when people are exploring personal relationships.  

Erikson believed it was vital that people develop close, committed relationships with other people. Those who are successful at this step will form relationships that are enduring and secure.

Building On Earlier Stages

Remember that each step builds on skills learned in previous steps. Erikson believed that a strong  sense of personal identity  was important for developing intimate relationships. Studies have demonstrated that those with a poor sense of self tend to have less committed relationships and are more likely to struggler with emotional isolation,  loneliness , and depression.

Successful resolution of this stage results in the virtue known as love. It is marked by the ability to form lasting, meaningful relationships with other people.

Stage 7: Generativity vs. Stagnation

Adults need to create or nurture things that will outlast them, often by having children or creating a positive change that benefits other people. Success leads to feelings of usefulness and accomplishment, while failure results in shallow involvement in the world.

During adulthood, we continue to build our lives, focusing on our career and family. Those who are successful during this phase will feel that they are contributing to the world by being active in their home and community.   Those who fail to attain this skill will feel unproductive and uninvolved in the world.

Care is the virtue achieved when this stage is handled successfully. Being proud of your accomplishments, watching your children grow into adults, and developing a sense of unity with your life partner are important accomplishments of this stage.

Stage 8: Integrity vs. Despair

The final psychosocial stage occurs during old age and is focused on reflecting back on life.   At this point in development, people look back on the events of their lives and determine if they are happy with the life that they lived or if they regret the things they did or didn't do.

Erikson's theory differed from many others because it addressed development throughout the entire lifespan, including old age. Older adults need to look back on life and feel a sense of fulfillment. Success at this stage leads to feelings of wisdom, while failure results in regret, bitterness, and despair.

At this stage, people reflect back on the events of their lives and take stock. Those who look back on a life they feel was well-lived will feel satisfied and ready to face the end of their lives with a sense of peace. Those who look back and only feel regret will instead feel fearful that their lives will end without accomplishing the things they feel they should have.​

Those who are unsuccessful during this stage will feel that their life has been wasted and may experience many regrets. The person will be left with feelings of bitterness and despair.

Those who feel proud of their accomplishments will feel a sense of integrity. Successfully completing this phase means looking back with few regrets and a general feeling of satisfaction. These individuals will attain   wisdom, even when confronting death.

Strengths and Weaknesses of Erikson's Theory

Erikson's theory also has its limitations and attracts valid criticisms. What kinds of experiences are necessary to successfully complete each stage? How does a person move from one stage to the next?

One major weakness of psychosocial theory is that the exact mechanisms for resolving conflicts and moving from one stage to the next are not well described or developed. The theory fails to detail exactly what type of experiences are necessary at each stage in order to successfully resolve the conflicts and move to the next stage.

One of the strengths of psychosocial theory is that it provides a broad framework from which to view development throughout the entire lifespan. It also allows us to emphasize the social nature of human beings and the important influence that social relationships have on development.

Researchers have found evidence supporting Erikson's ideas about identity and have further identified different sub-stages of identity formation.   Some research also suggests that people who form strong personal identities during adolescence are better capable of forming intimate relationships during early adulthood. Other research suggests, however, that identity formation and development continues well into adulthood.  

Why Was Erikson's Theory Important?

The theory was significant because it addressed development throughout a person's life, not just during childhood. It also stressed the importance of social relationships in shaping personality and growth at each point in development.

A Word From Verywell

It is important to remember that the psychosocial stages are just one theory of personality development . Some research may support certain aspects of this theoretical framework, but that does not mean that every aspect of the theory is supported by evidence. The theory can, however, be a helpful way to think about some of the different conflicts and challenges that people may face as they go through life.

It is also easy to look at each stage of Erikson's theory and consider how it can apply to your life. Learning about each stage can provide insight into what you might face as you age. It can also help you reflect on things that may have happened in the past and help you see ways you might be able to improve your coping skills to better deal with today's challenges.

Vogel-Scibilia SE, McNulty KC, Baxter B, Miller S, Dine M, Frese FJ. The recovery process utilizing Erikson's stages of human development . Community Ment Health J . 2009;45(6):405-14. doi:10.1007/s10597-009-9189-4

Malone JC, Liu SR, Vaillant GE, Rentz DM, Waldinger RJ. Midlife Eriksonian psychosocial development: Setting the stage for late-life cognitive and emotional health . Dev Psychol . 2016;52(3):496-508. doi:10.1037/a0039875

Orenstein GA, Lewis L. Erikson's Stages of Psychosocial Development. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing.

Meeus W, van de Schoot R, Keijsers L, Branje S. Identity statuses as developmental trajectories: A five-wave longitudinal study in early-to-middle and middle-to-late adolescents .  J Youth Adolesc . 2012;41(8):1008-1021. doi:10.1007/s10964-011-9730-y

Fadjukoff P, Pulkkinen L, Kokko K. Identity formation in adulthood: A longitudinal study from age 27 to 50 .  Identity (Mahwah, N J) . 2016;16(1):8-23. doi:10.1080/15283488.2015.1121820

Carver, CS & Scheir, MF.  Perspectives on Personality . Needham Heights, MA: Allyn & Bacon; 2011.

• Erikson, E.H. Childhood and Society . (2nd ed.). New York: Norton; 1993.
• Erikson, EH & Erikson, JM. The Life Cycle Completed. New York: Norton; 1998.

By Kendra Cherry, MSEd Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."