essay on developmental milestones

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About Child Development Stages

Categories: Child Children

About this sample

Words: 691 |

Published: Jan 4, 2019

Words: 691 | Pages: 2 | 4 min read

Giving praise for achievement
Giving children guidance but respecting their choices
Giving them the chance to meet and spend time with other children and adults
Providing activities that involve sharing and taking turns
Giving support and encouragement and the right amount of supervision
Providing opportunities to share in decisions
Listening to children and taking them seriously
Providing opportunities where children take responsibility
12-19 years

Works Cited

Centers for Disease Control and Prevention. (2021). Learn the signs. Act early. Milestones. Retrieved from https://www.cdc.gov/ncbddd/spanish/actearly/milestones/index.html
National Association for the Education of Young Children (NAEYC). (n.d.). Child development: A closer look. Retrieved from https://www.naeyc.org/our-work/families/child-development/closer-look
Raver, C. C., Blair, C., & Willoughby, M. (2013). Poverty as a predictor of 4-year-olds' executive function: New perspectives on models of differential susceptibility. Developmental Psychology, 49(2), 292-304. doi:10.1037/a0028343
Stein, A., Woolley, H., Senior, R., & Hertzman, C. (2008). Social inequalities in physical and mental health: Possible mechanisms and pathways. Journal of Child Psychology and Psychiatry, 49(6), 661-672. doi:10.1111/j.1469-7610.2008.01934.x
Zero to Three. (n.d.). Developmental milestones. Retrieved from https://www.zerotothree.org/resources/developmental-milestones
Kostelnik, M. J., Soderman, A. K., & Whiren, A. P. (2019). Developmentally appropriate curriculum: Best practices in early childhood education (7th ed.). Pearson.
Berk, L. E. (2020). Child development (10th ed.). Pearson.
Papalia, D. E., Olds, S. W., & Feldman, R. D. (2019). Human development (13th ed.). McGraw-Hill Education.
National Scientific Council on the Developing Child. (2014). Excessive stress disrupts the architecture of the developing brain. Working Paper No. 3. Retrieved from https://developingchild.harvard.edu/resources/wp3/
Pianta, R. C., & Walsh, D. J. (1996). High-risk children in schools: Constructing sustaining relationships. Routledge.

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Complete guide to developmental milestones, what's in this guide.

Thanks to the American Academy of Pediatrics for this content.

American Academy of Pediatrics healthychildren.org

Every child is different, and so is every parent’s experience; but experts have a clear idea about the range of normal development from birth to age 5 — and signs that a child might have a developmental delay. Below you’ll find milestones organized by period of development, and tips on when to contact a health professional about your concerns. Remember — there is no penalty for being cautious about your growing child, and if there is a problem acting early can make all the difference .

Milestones at 1 Month

Movement milestones.

Makes jerky, quivering arm thrusts
Brings hands within range of eyes and mouth
Moves head from side to side while lying on stomach
Head flops backward if unsupported
Keeps hands in tight fists
Strong reflex movements

Visual and Hearing Milestones

Focuses 8 to 12 inches (20.3 to 30.4 cm) away
Eyes wander and occasionally cross
Prefers black-and-white or high-contrast patterns
Prefers the human face to all other patterns
Hearing is fully mature
Recognizes some sounds
May turn toward familiar sounds and voices

Smell and Touch Milestones

Prefers sweet smells
Avoids bitter or acidic smells
Recognizes the scent of his own mother’s breastmilk
Prefers soft to coarse sensations
Dislikes rough or abrupt handling

Developmental Health Watch

If, during the second, third, or fourth weeks of your baby’s life, she shows any of the following signs of developmental delay, notify your pediatrician.

Sucks poorly and feeds slowly
Doesn’t blink when shown a bright light
Doesn’t focus and follow a nearby object moving side to side
Rarely moves arms and legs; seems stiff
Seems excessively loose in the limbs, or floppy
Lower jaw trembles constantly, even when not crying or excited
Doesn’t respond to loud sounds

Milestones at 3 Months

Raises head and chest when lying on stomach
Supports upper body with arms when lying on stomach
Stretches legs out and kicks when lying on stomach or back
Opens and shuts hands
Pushes down on legs when feet are placed on a firm surface
Brings hand to mouth
Takes swipes at dangling objects with hands
Grasps and shakes hand toys
Watches faces intently
Follows moving objects
Recognizes familiar objects and people at a distance
Starts using hands and eyes in coordination
Smiles at the sound of your voice
Begins to babble
Begins to imitate some sounds
Turns head toward direction of sound

Social and Emotional Milestones

Begins to develop a social smile
Enjoys playing with other people and may cry when playing stops
Becomes more communicative and expressive with face and body
Imitates some movements and facial expressions

Although each baby develops in her own individual way and at her own rate, failure to reach certain milestones may signal medical or developmental problems requiring special attention. If you notice any of the following warning signs in your infant at this age, discuss them with your pediatrician.

Doesn’t seem to respond to loud sounds
Doesn’t notice her hands by two months
Doesn’t smile at the sound of your voice by two months
Doesn’t follow moving objects with her eyes by two to three months
Doesn’t grasp and hold objects by three months
Doesn’t smile at people by three months
Cannot support her head well at three months
Doesn’t reach for and grasp toys by three to four months
Doesn’t babble by three to four months
Doesn’t bring objects to her mouth by four months
Begins babbling, but doesn’t try to imitate any of your sounds by four months
Doesn’t push down with her legs when her feet are placed on a firm surface by four months
Has trouble moving one or both eyes in all directions
Crosses her eyes most of the time (Occasional crossing of the eyes is normal in these first months.)
Doesn’t pay attention to new faces, or seems very frightened by new faces or surroundings
Still has the tonic neck reflex at four to five months

Milestones at 7 Months

Rolls both ways (front to back, back to front)
Sits with, and then without, support of her hands
Supports her whole weight on her legs
Reaches with one hand
Transfers object from hand to hand
Uses raking grasp (not pincer)

Visual Milestones

Develops full color vision
Distance vision matures
Ability to track moving objects improves

Language Milestones

Responds to own name
Begins to respond to “no”
Distinguishes emotions by tone of voice
Responds to sound by making sounds
Uses voice to express joy and displeasure
Babbles chains of consonants

Cognitive Milestones

Finds partially hidden object
Explores with hands and mouth
Struggles to get objects that are out of reach
Enjoys social play
Interested in mirror images
Responds to other people’s expressions of emotion and appears joyful often

Because each baby develops in his own particular manner, it’s impossible to tell exactly when or how your child will perfect a given skill. The developmental milestones listed in this book will give you a general idea of the changes you can expect, but don’t be alarmed if your own baby’s development takes a slightly different course. Alert your pediatrician, however, if your baby displays any of the following signs of possible developmental delay for this age range.

Seems very stiff, with tight muscles
Seems very floppy, like a rag doll
Head still flops back when body is pulled up to a sitting position
Reaches with one hand only
Refuses to cuddle
Shows no affection for the person who cares for him
Doesn’t seem to enjoy being around people
One or both eyes consistently turn in or out
Persistent tearing, eye drainage, or sensitivity to light
Does not respond to sounds around him
Has difficulty getting objects to his mouth
Does not turn his head to locate sounds by four months
Doesn’t roll over in either direction (front to back or back to front) by five months
Seems inconsolable at night after five months
Doesn’t smile spontaneously by five months
Cannot sit with help by six months
Does not laugh or make squealing sounds by six months
Does not actively reach for objects by six to seven months
Doesn’t follow objects with both eyes at near (1 foot) [30 cm] and far (6 feet) [180 cm] ranges by seven months
Does not bear some weight on legs by seven months
Does not try to attract attention through actions by seven months
Does not babble by eight months
Shows no interest in games of peekaboo by eight months

Milestones at 1 Year

Gets to sitting position without assistance
Crawls forward on belly by pulling with arms and pushing with legs
Assumes hands-and-knees position
Creeps on hands and knees supporting trunk on hands and knees
Gets from sitting to crawling or prone (lying on stomach) position
Pulls self up to stand
Walks holding on to furniture
Stands momentarily without support
May walk two or three steps without support

Milestones In Hand and Finger Skills

Uses pincer grasp
Bangs two cubes together
Puts objects into container
Takes objects out of container
Lets objects go voluntarily
Pokes with index finger
Tries to imitate scribbling
Pays increasing attention to speech
Responds to simple verbal requests
Responds to “no”
Uses simple gestures, such as shaking head for “no”
Babbles with inflection
Says “dada” and “mama”
Uses exclamations, such as “oh-oh!”
Tries to imitate words
Explores objects in many different ways (shaking, banging, throwing, dropping)
Finds hidden objects easily
Looks at correct picture when the image is named
Imitates gestures
Begins to use objects correctly (drinking from cup, brushing hair, dialing phone, listening to receiver)
Shy or anxious with strangers
Cries when mother or father leaves
Enjoys imitating people in play
Shows specific preferences for certain people and toys
Tests parental responses to his actions during feedings (What do you do when he refuses a food?)
Tests parental responses to his behavior (What do you do if he cries after you leave the room?)
May be fearful in some situations
Prefers mother and/or regular caregiver over all others
Repeats sounds or gestures for attention
Finger-feeds himself
Extends arm or leg to help when being dressed

Each baby develops in his own manner, so it’s impossible to tell exactly when your child will perfect a given skill. Although the developmental milestones listed in this book will give you a general idea of the changes you can expect as your child gets older, don’t be alarmed if his development takes a slightly different course. Alert your pediatrician if your baby displays any of the following signs of possible developmental delay in the eight-to twelve-month age range.

Does not crawl
Drags one side of body while crawling (for over one month)
Cannot stand when supported
Does not search for objects that are hidden while he watches
Says no single words (“mama” or “dada”)
Does not learn to use gestures, such as waving or shaking head
Does not point to objects or pictures

Milestones at 2 Years

Movement milestones.

Walks alone
Pulls toys behind her while walking
Carries large toy or several toys while walking
Begins to run
Stands on tiptoe
Kicks a ball
Climbs onto and down from furniture unassisted
Walks up and down stairs holding on to support

Milestones in hand and finger skills

Scribbles spontaneously
Turns over container to pour out contents
Builds tower of four blocks or more
Might use one hand more frequently than the other

Language milestones

Points to object or picture when it’s named for him
Recognizes names of familiar people, objects, and body parts
Says several single words (by fifteen to eighteen months)
Uses simple phrases (by eighteen to twenty-four months)
Uses two- to four-word sentences
Follows simple instructions
Repeats words overheard in conversation

Cognitive milestones

Finds objects even when hidden under two or three covers
Begins to sort by shapes and colors
Begins make-believe play

Social and emotional milestones

Imitates behavior of others, especially adults and older children
Increasingly aware of herself as separate from others
Increasingly enthusiastic about company of other children
Demonstrates increasing independence
Begins to show defiant behavior
Increasing episodes of separation anxiety toward midyear, then they fade

Developmental health watch

Because each child develops at his own particular pace, it’s impossible to tell exactly when yours will perfect a given skill. The developmental milestones will give you a general idea of the changes you can expect as your child gets older, but don’t be alarmed if he takes a slightly different course. Alert your pediatrician, however, if he displays any of the following signs of possible developmental delay for this age range.

Cannot walk by eighteen months
Fails to develop a mature heel-toe walking pattern after several months of walking, or walks exclusively on his toes
Does not speak at least fifteen words by eighteen months
Does not use two-word sentences by age two
Does not seem to know the function of common household objects (brush, telephone, bell, fork, spoon) by fifteen months
Does not imitate actions or words by the end of this period
Does not follow simple instructions by age two
Cannot push a wheeled toy by age two

Milestones at 4 Years

Hops and stands on one foot up to five seconds
Goes upstairs and downstairs without support
Kicks ball forward
Throws ball overhand
Catches bounced ball most of the time
Moves forward and backward with agility
Copies square shapes
Draws a person with two to four body parts
Uses scissors
Draws circles and squares
Begins to copy some capital letters
Understands the concepts of “same” and “different”
Has mastered some basic rules of grammar
Speaks in sentences of five to six words
Speaks clearly enough for strangers to understand
Tells stories
Correctly names some colors
Understands the concept of counting and may know a few numbers
Approaches problems from a single point of view
Begins to have a clearer sense of time
Follows three-part commands
Recalls parts of a story
Understands the concept of same/different
Engages in fantasy play
Interested in new experiences
Cooperates with other children
Plays “Mom” or “Dad”
Increasingly inventive in fantasy play
Dresses and undresses
Negotiates solutions to conflicts
More independent
Imagines that many unfamiliar images may be “monsters”
Views self as a whole person involving body, mind, and feelings
Often cannot distinguish between fantasy and reality

Because each child develops in his own particular manner, it’s impossible to tell exactly when or how he’ll perfect a given skill. The developmental milestones listed here will give you a general idea of the changes you can expect as your child gets older, but don’t be alarmed if his development takes a slightly different course. Alert your pediatrician, however, if your child displays any of the following signs of possible developmental delay for this age range.

Cannot throw a ball overhand
Cannot jump in place
Cannot ride a tricycle
Cannot grasp a crayon between thumb and fingers
Has difficulty scribbling
Cannot stack four blocks
Still clings or cries whenever his parents leave him
Shows no interest in interactive games
Ignores other children
Doesn’t respond to people outside the family
Doesn’t engage in fantasy play
Resists dressing, sleeping, using the toilet
Lashes out without any self-control when angry or upset
Cannot copy a circle
Doesn’t use sentences of more than three words
Doesn’t use “me” and “you” appropriately

Milestones at 5 Years

Stands on one foot for ten seconds or longer
Hops, somersaults
Swings, climbs
May be able to skip
Copies triangle and other geometric patterns
Draws person with body
Prints some letters
Dresses and undresses without assistance
Uses fork, spoon, and (sometimes) a table knife
Usually cares for own toilet needs
Recalls part of a story
Speaks sentences of more than five words
Uses future tense
Tells longer stories
Says name and address
Can count ten or more objects
Correctly names at least four colors
Better understands the concept of time
Knows about things used every day in the home (money, food, appliances)
Wants to please friends
Wants to be like her friends
More likely to agree to rules
Likes to sing, dance, and act
Shows more independence and may even visit a next-door neighbor by herself
Aware of sexuality
Able to distinguish fantasy from reality
Sometimes demanding, sometimes eagerly cooperative

Because each child develops in her own particular manner, it’s impossible to predict exactly when or how your own preschooler will perfect a given skill. The developmental milestones listed here will give you a general idea of the changes you can expect as your child gets older, but don’t be alarmed if her development takes a slightly different course. Alert your pediatrician, however, if your child displays any of the following signs of possible developmental delay for this age range.

Exhibits extremely fearful or timid behavior
Exhibits extremely aggressive behavior
Is unable to separate from parents without major protest
Is easily distracted and unable to concentrate on any single activity for more than five minutes
Shows little interest in playing with other children
Refuses to respond to people in general, or responds only superficially
Rarely uses fantasy or imitation in play
Seems unhappy or sad much of the time
Doesn’t engage in a variety of activities
Avoids or seems aloof with other children and adults
Doesn’t express a wide range of emotions
Has trouble eating, sleeping, or using the toilet
Can’t differentiate between fantasy and reality
Seems unusually passive
Cannot understand two-part commands using prepositions (“Put the cup on the table”; “Get the ball under the couch.”)
Can’t correctly give her first and last name
Doesn’t use plurals or past tense properly when speaking
Doesn’t talk about her daily activities and experiences
Cannot build a tower of six to eight blocks
Seems uncomfortable holding a crayon
Has trouble taking off her clothing
Cannot brush her teeth efficiently
Cannot wash and dry her hands

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About Pathways.org

Baby Milestones and Child Milestones to Track Development

What are developmental milestones.

Milestones are behavioral or physical checkpoints in children’s development as they grow. All of our developmental milestones are validated by American Academy of Pediatrics findings. Baby milestones and child milestones are core skills infants and toddlers should be reaching.

How are the developmental baby milestones organized?

We have divided our developmental milestones into the core parts of child development:

Motor milestones
Sensory milestones
Communication milestones
Feeding milestones

Why are baby milestones and child milestones in age ranges?

Baby milestones and child milestones are in age ranges (such as 0-3 months or 2-3 years) because all babies are different! Milestones mark the months most babies start a certain behavior or ability based on baby’s age, but exact timing will vary.

What is the best way to track baby milestones and child milestones?

Use the FREE Pathways.org Baby Milestones app to track your little one’s progress! Download the app and enter baby’s birthdate to see all their milestones and track their progress. You can watch videos of each milestone to be sure that baby has met it!

Learn more and download the FREE Pathways.org Baby Milestones app!

Want these milestones in a handheld guide?

Order Baby's First Year Milestone Guide

Can I still track baby milestones and child milestones if baby was born premature?

Yes! If baby was born early, you can accurately track their milestones by adjusting for prematurity . If you download the Pathways.org Baby Milestones app and indicate that baby was premature, the app will automatically adjust their milestones for you! It is recommended that baby’s milestones remain adjusted until they reach 2 years old.

What should I do if my child missed a milestone?

If your child is missing any milestones, be sure to talk with your healthcare provider.

Early detection allows for early correction or support. I have witnessed the effect this has a on child’s trajectory hundreds of times over my pediatric career. My favorite time is looking back with parents when their children are older and reflecting on the significance of early intervention. We are both grateful.

-Lori Walsh, MD, FAAP

Be sure to adjust for prematurity . If your child is missing any milestones, be sure to talk with your healthcare provider.

0-3 Month Milestones

Motor milestones.

While lying on tummy, pushes up on arms
While lying on tummy, lifts and holds head up
Able to move fists from closed to open
Able to bring hands to mouth
Moves legs and arms off of surface when excited

Sensory Milestones

While lying on back, attempts to reach for a toy held above their chest
While lying on back, visually tracks a moving toy from side to side
While lying on back, keeps head centered to watch faces or toys
Able to calm with rocking, touching, and gentle sounds
Enjoys a variety of movements

Communication Milestones

Quiets or smiles in response to sound or voice
Turns head towards sound or voice
Shows interest in faces
Makes eye contact
Cries differently for different needs (e.g. hungry vs. tired)
Coos and smiles

Feeding Milestones

Latches onto nipple or bottle
Tongue moves forward and back to suck
Drinks 2 oz. to 6 oz. of liquid per feeding, 6 times per day
Sucks and swallows well during feeding

See Videos of 0-3 Month Milestones

4-6 Month Milestones

Uses hands to support self while sitting
Rolls from back to tummy and tummy to back
While standing with support, accepts entire weight with legs
Reaches for nearby toys while on tummy
While lying on back, reaches both hands to play with feet
While lying on back, transfers a toy from one hand to the other
Uses both hands to explore toys
Generally happy when not hungry or tired
Brings hands and objects to mouth
Is not upset by everyday sounds
Reacts to sudden noises or sounds
Listens and responds when spoken to
Begins to use consonant sounds in babbling, e.g. “da, da, da”
Makes different kinds of sounds to express feelings
Notices toys that make sounds
Uses babbling to get attention
Shows interest in food
Opens mouth as spoon approaches
Moves pureed food from front of mouth to back
Begins to eat cereals and pureed foods – Smooth, pureed food (single ingredient only), like carrots, sweet potato, squash, apples, pears

See Videos of 4-6 Month Milestones

7-9 Month Milestones

Sits without support
Sits and reaches for toys without falling
Moves from tummy or back into sitting
Starts to move with alternate leg and arm movement e.g. creeping, crawling
Picks up head and pushes through elbows during Tummy Time
Turns head to visually track objects while sitting
Shows more control while rolling and sitting
Picks up small objects with thumbs and fingers
In simple play imitates others
Enjoys a variety of movements – bouncing up and down, rocking back and forth
Explores and examines an object using both hands and mouth
Turns several pages of a chunky (board) book at once
Experiments with the amount of force needed to pick up different objects
Focuses on objects near and far
Investigates shapes, sizes, and textures of toys and surroundings
Observes environment from a variety of positions – while lying on back or tummy, sitting, crawling, and standing with assistance
Uses increased variety of sounds and syllable combinations in babbling
Looks at familiar objects and people when named
Recognizes sound of their name
Participates in two-way communication
Follows some routine commands when paired with gestures
Shows recognition of commonly used words
Simple gestures, e.g. shaking head for “no”
Imitates sounds
In a highchair, holds and drinks from a bottle
Begins to eat thicker pureed and mashed table foods
Enjoys chew toys that can massage sore and swollen gums during teething
Stays full longer after eating
Starts to look and reach for objects, such as, food that is nearby
Shows strong reaction to new smells and tastes

See Videos of 7-9 Month Milestones

10-12 Month Milestones

Pulls to stand and cruises along furniture
Stands alone and takes several independent steps
Moves in and out of various positions to explore environment and get desired toys
Maintains balance in sitting when throwing objects
Claps hands
Releases objects into a container with a large opening
Uses thumb and pointer finger to pick up tiny objects
Enjoys listening to songs
Explores toys with fingers and mouth
Crawls to or away from objects baby sees in the distance
Meaningfully uses “mama” or “dada”
Responds to simple directions, e.g. “Come here”
Produces long strings of gibberish (jargoning) in social communication
Says one or two words
Imitates speech sounds
Babbling has sounds and rhythms of speech
Pays attention to where you are looking and pointing
Responds to “no”
Begins using hand movements to communicate wants and needs, e.g. reaches to be picked up
Finger feeds self
Eating an increasing variety of food
Begins to use an open cup
Ready to try soft-cooked vegetables, soft fruits, and finger foods (banana slices, cooked pasta)
Might be ready to start self feeding with utensils
Enjoys a greater variety of smells and tastes

See Videos of 10-12 Month Milestones

13-18 Month Milestones

Walks independently
Squats to pick up a toy
Stacks two objects
Helps with getting dressed/undressed
Has a regular sleep schedule
Eats an increasing variety of foods

By 15 months:

May use 5-10 words
Combines sounds and gestures
Imitates simple words and actions
Consistently follows simple directions
Shows interest in pictures
Can identify 1-2 body parts when named
Understands 50 words

By 18 months:

Responds to questions
Repeats words overheard in conversation
Continues to produce speech-like babbling
Points at familiar objects and people in pictures
Understands “in” and “on”
Responds to yes/no questions with head shake/nod
Increases variety of coarsely chopped table foods
Holds and drinks from a cup

See Videos of 13-18 Month Milestones

19-24 Month Milestones

Starts to jumps with both feet leaving the ground
When walking, able to pull toys behind them
Stands on tiptoes
Climbs on low furniture
Kicks large ball
Goes up and down stairs with support
Flips switches on and off
Uses crayons, pens, or markers to make marks on paper
Sorts shapes and colors
Stacks 5 or more small blocks or toys on top of each other
Takes toys apart and puts them back together

By 21 Months:

Uses at least 50 words
Consistently imitates new words
Names objects and pictures
Understands simple pronouns (me, you, my)
Identifies 3-5 body parts when named
Understands new words quickly

By 24 months:

Begins to use 2 word phrases
Uses simple pronouns (me, you, my)
Understands action words
Uses gestures and words during pretend play
Follows 2-step related directions e.g. “Pick up your coat and bring it to me”
Enjoys listening to stories

See Videos of 19-24 Month Milestones

2-3 Year Milestones

By 30 months :

Consistently uses 2-3 word phrases
Uses “in” and “on”
At least 50% of speech is understood by caregiver
Follows 2-step unrelated directions, e.g. “give me the ball and go get your coat”
Understands basic nouns and pronouns
Understands “mine” and “yours”

By 36 months:

Asks “what” and “where” questions
Uses plurals, e.g. “dogs”
Most speech is understood by caregiver
Simple understanding of concepts including color, space, time
Understands “why” questions
Understands most simple sentences

Missing Milestones

What to do if your child is not reaching their key developmental milestones.

If your child is missing a developmental milestone, request an appointment with a healthcare provider to ask them about how you can get your baby on track!

Remember every baby is different, and milestones typically occur within a general age range.

Baby’s early years are some of the most important years for their development, which is why early detection and early intervention are so critical.

As a general pediatrician I often refer parents to the Pathways.org website for free videos and brochures on tummy time and the stages of infant development.

These resources empower parents to track their babies’ developmental progress and bring their concerns to me quickly so that we can provide resources in a timely and efficient manner.

-Karen R. Judy, M.D. FAAP

Resources to Meet Milestones

Browse our website for additional resources to maximize your child’s motor, sensory, feeding, and communication development!

Topics pages : Covering a wide variety of health topics for your baby’s developmental milestones.
Videos : Including milestone videos and Parents’ Guide videos, which shows baby’s development in action!
Blog posts : In-depth and healthcare provider-approved articles providing important health info to help learn the signs of a delay and when to request an appointment with a healthcare provider.
Baby’s First Year Milestone Guide : This helpful guide is a handheld milestone checklist for infants. Keep track of your baby’s developmental milestones through this organized, color-coded, and compact guide. The ultimate resource center for baby’s development!
The Baby Games Calendar : If baby enjoys playing, then check out these fun games for infants and toddlers! Baby Games make caring for your baby engaging and interactive, helping with everything from language development to hand eye coordination.

Developmental Psychology: Developmental Milestone

Introduction, overview of development theory, developmental milestone, the ‘who am i stage’.

Human development is a step-by-step process that takes a person’s lifetime. On the contrary, the development of the brain is active in childhood, adolescence, and early adulthood (Lemme, 2006, p. 56). In this essay, we consider the developmental milestone of a twelve-year-old male who moves to the UK and experiences a couple of problems while developing. These problems include: being bullied by other children in his new school, facing difficulties in adapting to the new school environment and the new country, experiencing loneliness etcetera. The age under consideration is twelve years to eighteen years.

Development theories explain how children develop their personality from the experiences they go through and how they also learn how to relate with others from their past experiences. Jean Piaget (1896 – 1980) and Erik Erikson (1902 – 1994), had a massive contribution to the development theory. According to Piaget and Erickson children develop in stages, each of which has a significant contribution to the development process. According to Erickson, if a child successfully completes a stage in the development process, he/she develops a better personality and it also contributes to his/her ability to develop healthy relationships with others. On the other hand, if a child does not successfully complete a stage, his/her personality and relationship with others are compromised (Siegel & Rider, 2009, p. 23).

In our developmental milestone, a twelve-year-old male moves to the UK. He faces problems including bullying in school, adjusting to both the school environment and the new country, and loneliness. As a result of this, he changes school three times in three years before settling down. Although most of the experiences this child undergoes are negative, they are arguably essential in developing him. Consider, for example, the bullying he suffers in school. It could have been other children putting him down, calling him names, saying/ writing inappropriate things about him, being excluded from activities, not being talked to, being hit etcetera. The possible explanations of why the other children would be bullies are the influence of the way they have been raised- children who do not bond with their parents tend to become bullies. Thus children unto whom disciplinary measures are instilled using coercion are more likely to become bullies. Another explanation could be due to the character of the child. For instance, if a child normally has irregular eating and sleeping habits, he/she is likely to become a bully. The bullying could have substantially contributed to building the perseverance of the child for him to settle later in a different school because we do not expect the school to lack its own problems (Randall, 2001, p. 57).

Next, consider the need to adapt to the new environment. This has negative effects on every reality of the child’s life ranging from the schooling part of life, socialization, leisure at home etcetera. In school, the child has to learn the temperaments of other children in the school. This condition may substantially lead to the development of the child’s understanding and compromising capability thus, in a way contributing to the development of the child’s personality. At home, he has to learn how to make new friends and also learn new social activities. This will help in developing his social skill of making friends and also develop his learning skills (Coy, 2001, p.54).

Loneliness also has its own pros and cons. The child will have to learn how to overcome loneliness and sometimes make the most of it when it can not be avoided. All in all, the difficulties that this child faces develop him progressively until he finds a way to escape them or learns to live with those that can not be overcome (Willis & Martin, 2005, p. 76).

The adolescent behavior seen in our developmental milestone can b explained by Erikson’s stage 5 of psychosocial development. This stage deals with the development of personal identity in adolescents and therefore, Erikson referred to it as the ‘who am I?’ stage. In this stage, which occurs in early teenage, adolescents are preoccupied with the establishment of personal identity and setting of goals defining what their future will be. According to Erikson, adolescents must develop an appropriate and stable self-concept failure to which an identity crisis occurs. Consequently, the adolescent will not be aware of the roles he/she is supposed to play in society and thus he/she does not establish a stable life ism. This will affect his/her development socially and career-wise. Thus the bullying and isolation of the child could be explained by the lack of self-identity of the perpetrators (Foos & Clark, 2003, p. 62).

The elements of self-identity developed in this stage include self-concept, self-esteem, and self-efficacy. Self-concept can be described as the awareness of self. That is, knowing the several aspects of self-identity. Self-esteem is the valuing of oneself and self-efficacy is the undeterred beliefs one has on specific issues and events. To form these aspects of self-identity, adolescents need to be aware of their past, establish goals and maintain adequate interpersonal relationships (Bee & Boyd, 2002, p. 49).

It is of great essence that adolescents understand the stages of psychosocial development and also be aware of what they are supposed to do to go through each stage successfully. This will enable them to make choices that will lead to success in careers and interpersonal relationships. It will also avoid the development of personality and identity crisis in adolescents and thus minimize uncouth adolescent behavior (Breyer & Winters, 2004, p. 56).

Although the social problems experienced by children are, in a way, beneficial to their personal development, it is wise to ensure that children develop their personality and values the easy way. Facing difficulties can never be a precondition for personal development. Thus, with our current level of civilization, such behaviors as bullying and social discrimination should not be tolerated in society. We should find a way of mitigating the contribution of psychological development to teenage mischief. There is a great need to educate adolescents about their development so that they can have an idea of how depriving the process of development can be. They should be aware of the various stages of development and the effects these stages are likely to have on their behavior which in turn affects their lives. With this kind of information, adolescents will be able to avoid detrimental behaviors towards their peers and thus we will be able to appreciate the diversity of culture and also be able to live in a variety of environments without problems.

Bee, H., & Boyd, D. (2002). Lifespan Development . (3 rd ed). London: Allyn & Bacon.

Breyer, J., & Winters, K. (2004). Adolescent brain development: Implications for drug Use prevention . New York: Mentor

Coy, D. (2001). Bullying ERIC Clearinghouse on Counseling and Student Services, North Carolina: Greensboro.

Foos, P., & Clark, M. (2003). Human Aging . Boston: Allyn & Bacon.

Lemme, B. (2006). Development in adulthood (4 th Ed) , Boston: Allyn & Bacon.

Randall, P. (2001). Bullying in Adulthood: Assessing the Bullies and Their Victims . London: Brunner- Routledge.

Siegel, C & Rider, E. (2009). Life-Span Human Development (6 th Ed.), Belmont, CA: Wadsworth Cengage Learning.

Willis, S., & Martin, M. (2005). Middle Adulthood: A lifespan perspective . CA. Sage.

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UConn KIDS (Kids in Developmental Science)

Child development stages and milestones.

Child development is a broad term that entails many milestones. A newborn and an 8 year old are at very different stages in development, and for this reason child development has been broken up into 5 distinct stages:

Birth to 18 months: children can learn to identify familiar faces and respond to facial expressions. They also have the ability to learn some words, stand, and walk by themselves.

18 months to 3 years: children can start pretend play and play with other children!

3 years to 5 years: children can start to express their likes, learn to count, and identify numbers. They also have the ability to play on their own.

5 years to 12 years: This is the age where children start grade school. Here they are able to develop their problem solving skills. They also can build close friendships and develop personal interests!

12 years to 18 years: This is the stage where adolescents start to grow their independence. They begin puberty, develop their own opinions and start to become interested in dating.

There are many milestones children and adolescents reach in the time of child development. These milestones refer to behaviors that mark stages of growth. It’s very important to remember that children develop at their own pace, and two children might not reach a specific milestone at the same time. Some milestones children reach are repeating familiar songs, remembering faces and names, and sorting shapes and colors.

If you’re concerned that your child is developmentally delayed it’s helpful to get them screened for any potential issues.

If you want to read more about child developmental stages and potential signs/causes of developmental delays read here!

Kaitlyn Vitucci, Research Assistant UConn KIDS

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5-Year-Old Child Development Milestones

Your child’s growth and development at age 5

Language and Cognitive Milestones
Movement Milestones
Emotional and Social Milestones
Other Milestones
Help Your 5-Year-Old Learn and Grow
Keep Your 5-Year-Old Safe
When to Be Concerned

Five years old can be a really fun age! Your child loves to play and is extremely imaginative. They still feel little and adorable, but they are becoming quite the conversationalist, and their ability to pick up new information and ask thoughtful questions will seriously impress you.

This age isn’t without its ups and downs. Five-year-olds are still learning to regulate their emotions, so meltdowns happen from time to time. Still, your child is moving toward becoming more mature, and is able to do big kid things like going to school , and brushing their own teeth.

Let’s take a look at what to expect in terms of growth and development as you parent your 5-year-old, as well as some red flags that might warrant a call to your pediatrician.

5-Year-Old Language and Cognitive Milestones

Your child’s language skills are really exploding at this age. “Five-year-olds are fluent talkers,” says Molly O'Shea , MD, official pediatrician of Goldfish Swim School . “They use pronouns correctly, recognize colors, and understand and use direction words like 'over,' 'under,' and 'next to.'”

Dr. O’Shea says that children this age love to recount the things that happened to them during the day, and can recall details from hours before. They are also able to carry out more detailed directions than they did before, a skill that will help prepare them for kindergarten.

“When following directions, five-year-olds can usually carry out a three-step sequence such as, ‘Get your shoes, put on your jacket, and pack your backpack,’ with few reminders,” Dr. O’Shea describes.

Cognitively, you will be wowed by how quickly your child is absorbing new information, says Tiffany Kimbrough, MD , associate professor and pediatrician at Children’s Hospital of Richmond at VCU. “Five-year-olds are like sponges and are constantly learning,” Dr. Kimbrough explains. “They can count ten or more items, can understand concepts like money, print letters and numbers, and copy shapes.”

Although your child still enjoys playing imaginatively, they are better able to distinguish between imaginative play and real life, says Dr. O'Shea. “Fantasy vs. reality are getting clearer, but kids still struggle to understand what can really happen and what can’t,” she notes.

Language and Cognitive Checklist

Five-year-olds have a vocabulary of about 2000 words, and speak in sentences with at least five words.
They can recount things like their phone number, and the first and last names of their parents.
They still ask a lot of questions, but they can also answer simple questions.
They can recognize rhymes, like "hop" and "stop."
Their speech is more easily understood by others, and they are starting to use the future tense when speaking (“I will go to school tomorrow”).

5-Year-Old Movement, Hand, and Finger Milestones

As your child moves from preschool age to school-age, they are growing a bit more slowly, and their round cheeks and chunky thighs may start to lean out a bit. At this age, your child will gain about 4 or 5 pounds a year, and grow about 5 to 8 centimeters. On average, 5-year-olds weigh roughly 40 pounds and are about 40 inches in height.

Your child is no longer a teetering toddler or preschooler. Their movements are becoming more synchronized and their hand-eye coordination is getting more refined.

“Five-year-olds have gotten a lot more coordinated and are ready for action,” Dr. O’Shea says. “Gross motor skill development allows them to throw and catch smaller balls, run, jump and skip, and even do more complex movements like gymnastics and swimming real strokes.” They should also be able to hop on one foot.

As for fine motor skills, your child should be able to do things like feed themselves easily, and may even be able to use a child-safe knife to do things like spread butter on bread. Your child’s writing skills are also improving, which is readying them for exciting things like printing their own name. They also have some ability to dress themselves, such as by buttoning large buttons.

“They should have established hand dominance and be exhibiting a mature pencil grasp called a dynamic tripod (or quadrupod) grasp,” explains Caitlin Sanschagrin, an occupational therapist at Bright SpOT Pediatric Therapy . But all children are different, Sanschagrin says, and you shouldn’t expect your child to have a “textbook” pencil grasp at this age.

Physical Milestones Checklist

Your 5-year-old should be able to stand on one foot for about 10 seconds.
They are mastering the art of climbing, swinging, and somersaulting.
They should be able to use the potty on their own.
They can hop, and may even be able to skip.

5-Year-Old Emotional and Social Milestones

One of the things you may notice at this age is just how much fun it is to chat with your 5-year-old. Yes, they still say the cutest things, but they also have a lot of interesting thoughts and opinions to share. “They are very capable of participating in conversations and may ask questions to gain information,” says Emily Rooker, a speech-language pathologist at Bright SpOT Pediatric Therapy.

Additionally, Rooker notes, your 5-year-old is growing and maturing when it comes to making friends and engaging with people outside their immediate family. At this age, children more consciously make and choose friends on their own, Rooker says.

They are also able to engage in play that involves directions, expectations, and cooperation, Rooker explains, which is another important prerequisite for the type of activities they will engage in once they begin elementary school. A 5-year-old can also do simple chores, such as putting their plate and cup in the sink after a meal.

But as much as your child is becoming more able to adhere to rules and become a team player, they are still very much capable of testing limits , especially with their parents. Regressing in behavior—and even having the occasional meltdown—is typical at this age, and it’s important to remember that you child is young and still learning.

“It can be frustrating for parents to see children behaving ‘like babies’ in their eyes, but by acknowledging the feelings and supporting the child, their emotional capabilities will grow and the child will have more ways of handling tough situations,” Dr. O’Shea advises.

Other Milestones for Your 5-Year-Old

Get your tooth fairy skills ready, because 5 years old is when most children start to lose their baby teeth. Starting at around age 5 or 6 is when your child’s mature sets of incisors (the middle bottom and middle top teeth) start to come in. The teeth will be wiggly for a few days or weeks before they fall out, and they often fall out while your child is eating. There may be a little blood, but the bleeding should be minimal.

At this age, your child should also be fully potty-trained, for both pee and poop. Most children this age can clean up after themselves in the bathroom as well. Don’t be surprised if your child still has accidents, though (that’s why their kindergarten teacher will have you send in an extra set of clothes). Kids this age still sometimes wet the bed.

How to Help Your 5-Year-Old Learn and Grow

As a parent, you may feel frustrated by the fact that your child still has occasional tantrums at 5 years old. This behavior is normal, says Dr. O’Shea, but there are some things you can do as a parent to help your child navigate these difficult feelings.

“Children will get upset,” she says. “When they do, parents can try hard to empathize rather than diminish their children’s feeling by saying things like ‘stop crying’ or ‘you’ll be fine.’” Even though your instinct as a parent may be to try to make the behavior stop immediately, allowing children a chance to share their emotions is important.

“By leaning into it with empathy, we give our children an opportunity to express their feelings and for us to help them come up with new ways to express themselves in the long run,” Dr. O’Shea offers.

How to Keep Your 5-Year-Old Safe

Your child will have a well checkup at the pediatrician's office soon after they turn 5. Their healthcare provider will make sure they are up to date with their immunizations , especially the ones required for school. Immunizations typically offered at this age include additional doses of the DTaP vaccine, the polio vaccine, the chickenpox vaccine, and the MMR vaccine. Your child’s provider will likely offer the flu shot as well.

Additionally, your child’s pediatrician will discuss the kinds of lifestyle choices that will keep your child healthy during this time. Five-year-olds need regular physical activity—at least one hour of movement a day. They need to get adequate sleep as well, and many kids this age need to sleep between 11 and 13 hours each night.

When to Be Concerned About Your 5-Year-Old

Every child is different when it comes to reaching milestones, and this is especially true at age 5. Some children are able to read a little at this age, while others are still learning their letters. Some children are little gymnasts while others are still mastering catching a ball . There is a wide range of normal, so don’t worry too much if your child has or hasn't mastered certain skills before others.

Still, there are some signs that your child may need a little extra help or an evaluation by a medical professional.

“If your child cannot say their first and last name, doesn't play with a variety of toys or play different games, doesn't respond to others, has extreme emotions (anxious, shy, or overly fearful), is unable to wash their own hands, cannot draw a picture, or if your child ever loses skills they once possessed, you should speak with your child's pediatrician or family practice doctor for more of an in-depth developmental assessment,” Dr. Kimbrough advises.

You can bring up your concerns with your pediatrician. If they agree that there may be an issue, they will be able to refer you to a specialist who can evaluate your child, and help them get the help they need.

A Word From Verywell

As you observe your 5-year-old and consider their growth and development, you probably have their entry into elementary school at the forefront of your mind. This is natural, because starting kindergarten is a major milestone for both you and your child.

Thankfully, although the adjustment to school can be bumpy, most children do fine in kindergarten—and yes, their parents learn to let go as well. But there are some children who struggle.

If you are concerned about your child’s ability to self-regulate their emotions, or if your child is showing lags in social skills or pre-reading and math skills, don’t hesitate to reach out to your pediatrician with your questions and concerns.

Centers for Disease Control and Prevention. Important milestones: Your child by five years .

Mott Children’s Hospital. Milestones for 5-year-olds .

U.S. National Library of Medicine. Developmental milestones record - 5 years .

Nemours KidsHealth. Growth and your 4- to 5-year-old .

Nemours KidsHealth. Your teeth .

Centers for Disease Control and Prevention. Vaccines at 4 to 6 years .

Nemours KidsHealth. Your child's checkup: 5 years .

By Wendy Wisner Wendy Wisner is a lactation consultant and writer covering maternal/child health, parenting, general health and wellness, and mental health. She has worked with breastfeeding parents for over a decade, and is a mom to two boys.

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National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Division of Behavioral and Social Sciences and Education; Board on Children, Youth, and Families; Committee on the Neurobiological and Socio-behavioral Science of Adolescent Development and Its Applications; Backes EP, Bonnie RJ, editors. The Promise of Adolescence: Realizing Opportunity for All Youth. Washington (DC): National Academies Press (US); 2019 May 16.

The Promise of Adolescence: Realizing Opportunity for All Youth.

Hardcopy Version at National Academies Press

2 Adolescent Development

A dolescence is a period of significant development that begins with the onset of puberty 1 and ends in the mid-20s. Consider how different a person is at the age of 12 from the person he or she is at age 24. The trajectory between those two ages involves a profound amount of change in all domains of development—biological, cognitive, psychosocial, and emotional. Personal relationships and settings also change during this period, as peers and romantic partners become more central and as the adolescent moves into and then beyond secondary school or gains employment.

Importantly, although the developmental plasticity that characterizes the period makes adolescents malleable, malleability is not synonymous with passivity. Indeed, adolescents are increasingly active agents in their own developmental process. Yet, as they explore, experiment, and learn, they still require scaffolding and support, including environments that bolster opportunities to thrive. A toxic environment makes healthy adolescent development challenging. Ultimately, the transformations in body, brain, and behavior that occur during adolescence interact with each other and with the environment to shape pathways to adulthood.

Each stage of life depends on what has come before it, and young people certainly do not enter adolescence with a “blank slate.” Rather, adolescent development is partly a consequence of earlier life experiences. However, these early life experiences are not determinative, and the adaptive plasticity of adolescence marks it as a window of opportunity for change through which mechanisms of resilience, recovery, and development are possible. ( Chapter 3 discusses this life-course perspective on development in detail.) This chapter explores three key domains of adolescent development: puberty, neurobiological development, and psychosocial development. Within each domain, we highlight processes that reflect the capacity for adaptive plasticity during adolescence and beyond, marking adolescence as a period of unique opportunity for positive developmental trajectories.

Puberty, a normative developmental transition that all youth experience, is shaped by both social and biological processes. Although often misconstrued as an abrupt, discrete event, puberty is actually a gradual process occurring between childhood and adolescence and one that takes many years to complete ( Dorn and Biro, 2011 ). Biologically, puberty involves a series of complex alterations at both the neural and endocrine levels over an extended period that result in changes in body shape (morphology), including the maturation of primary and secondary sex characteristics during late childhood and early adolescence and, ultimately, the acquisition of reproductive maturity ( Dorn and Biro, 2011 ; Natsuaki et al., 2014 ).

Two biological components of puberty, adrenarche and gonadarche , are relevant in understanding the link between puberty and adolescent wellbeing. Adrenarche, which typically begins between ages 6 and 9, refers to the maturation of the hypothalamic-pituitary-adrenal (HPA) axis, during which the levels of adrenal androgens (e.g., dehydroepiandrosterone and its sulfate) begin to increase. While adrenarche begins in late childhood, levels of adrenarchal hormones continue to rise throughout adolescence, peaking in the early 20's ( Blakemore et al., 2010 ). Adrenal androgens contribute to the growth of pubic and axillary hair. Gonadarche typically begins in early adolescence, at approximately ages 9 to 11, and involves the reactivation of the hypothalamic-pituitary-gonadal (HPG) axis (for a review, see Sisk and Foster, 2004 ). 2 The rise of gonadal steroid hormones to adult levels occurs as a result of HPG reactivation and is primarily responsible for breast and genital development in girls.

The consequence of these complex changes in HPA and HPG axes at the neuroendocrine level is a coordinated series of visible, signature changes in body parts. These include a growth spurt, changes in skin (e.g., acne) and in body odor, the accumulation of body fat (in girls), the appearance of breast budding (in girls) and enlargement of testes and increased penis size (in boys), the growth of pubic and axillary hair, the growth of facial hair (in boys), and the arrival of the first period (i.e., menarche, in girls). Key pubertal events are highlighted in Figure 2-1 ; however, as discussed next, there is a great deal of variation in the timing and tempo of these events.

Key pubertal events across adolescence.

It is useful to distinguish three distinct yet interrelated ways to conceptualize individual differences in pubertal maturation. Pubertal status refers to how far along adolescents are in the continuum of pubertal maturation at any given moment. For instance, if an 11-year-old girl has just experienced menarche, she is considered to have advanced pubertal status because menarche is the last event that occurs in the process of the female pubertal transition. Pubertal status is inherently confounded with age, because older adolescents are more likely to have attained advanced pubertal status.

Pubertal timing , on the other hand, refers to how mature an adolescent is when compared to his or her same-sex peers who are of the same age. In other words, pubertal timing always includes a reference group of one's peers. For example, a girl who experiences menarche at age 10 may be an earlier maturer in the United States, because her menarcheal timing is earlier than the national average age for menarche nationwide, which was found to be 12.4 years in a cohort of girls born between 1980 and 1984 ( McDowell et al., 2007 ). Only 10 percent of girls in the United States are estimated to have experienced menarche before 11.11 years of age ( Chumlea et al., 2003 ), suggesting that the girl in this example would be considered to have early pubertal timing. Unlike pubertal status, pubertal timing is not confounded by age because, by definition, pubertal timing is inherently standardized within same-sex, same-age peers typically residing in the same country.

Pubertal tempo is a within-the-individual metric that refers to how quickly a person completes these sets of pubertal changes. For example, some boys may experience a deepening of their voice and the development of facial, axillary, and pubic hair all within a matter of months, whereas other boys may have a gap of several years between voice-deepening and the development of facial hair. Pubertal tempo has gained more attention recently with the rise of sophisticated longitudinal methodology and the resulting availability of longitudinal data on pubertal maturation (e.g., Ge et al., 2003 ; Marceau et al., 2011 ; Mendle et al., 2010 ).

Regardless of the metric used, most of the research on adolescent pubertal development has focused on girls. We know comparatively little about the processes, correlates, and outcomes of pubertal maturation in boys, except for the well-replicated findings that girls typically begin and complete puberty before boys. Evidence is now emerging that the relationship between puberty and structural brain development in the amygdala and hippocampus region may differ by sex ( Satterthwaite et al., 2014 ; Vijayakumar et al., 2018 ). These sex differences in associations between brain development and puberty are relevant for understanding psychiatric disorders characterized by both hippocampal dysfunction and prominent gender disparities during adolescence.

It is also important to consider the pubertal development of transgender and gender-nonconforming youth. Transgender and gender-nonconforming individuals usually identify as a gender other than the one they were assigned at birth ( Sylvia Rivera Law Project, 2012 ). Individuals who are gender-nonconforming may identify as transgender, genderqueer, gender-fluid, gender-expansive, or nonbinary. Puberty is a time that can be enormously stressful, and the fear of developing—or the actual development of—secondary sexual characteristics that do not match a child's gender identity can be intense and even destabilizing ( de Vries et al., 2011 ). Some transgender and gender-nonconforming youth might take medications that block puberty. Although puberty blockers have the potential to ease the process of transitioning, the long-term health effects of these drugs are not yet known ( Boskey, 2014 ; Kreukels and Cohen-Kettenis, 2011 ).

The Role of Early Experiences on Pubertal Timing and Tempo

As noted earlier, the timing and rate of pubertal development vary greatly. The age at which someone matures is due to a combination of genetic and environmental influences (e.g., Mustanski et al., 2004 ). Early life experiences, including social risks and disadvantages, have been shown to accelerate pubertal tempo and lower the age of pubertal timing ( Marshall and Tanner, 1969 ). Specifically, accelerated pubertal tempo and early pubertal timing have been associated with stressors, including childhood sexual abuse and physical abuse, obesity, prematurity, light exposure, father absence, and exposure to endocrine disruptors (such as chemicals in plastics, pesticides, hair-care products, and many meat and dairy items) (see e.g., Steinberg, 2014 , pp. 54–55). This section reviews the literature on associations between these early experiences and normative variations in pubertal timing and tempo. We close this section with a brief discussion of these associations as a marker of adaptive plasticity.

Maltreatment

One of the most widely studied early experiences related to pubertal development is child maltreatment, and in particular, sexual abuse. A series of studies shows that the age of menarche tends to be lower for girls who experienced child sexual abuse as compared to girls who have not experienced this ( Bergevin et al., 2003 ; Natsuaki et al., 2011 ; Romans et al., 2003 ; Turner et al., 1999 ; Wise et al., 2009 ). Trickett and Putnam (1993) suggested that the trauma of child sexual abuse introduces physiological as well as psychological consequences for children, including accelerated maturation by premature activation of the HPA and HPG axes. In addition, some studies have observed a relationship between childhood physical abuse and early maturation, though less robustly and less consistently than for sexual abuse ( Bergevin et al., 2003 ; Wise et al., 2009 ), and these studies do not always control for the possibility of concurrent sexual abuse (e.g., Romans et al., 2003 ).

In one of the few studies to examine pubertal development longitudinally in adolescents with maltreatment histories, Mendle and colleagues (2011) followed a sample of 100 girls in foster care at four points in time over 2 years, beginning in the spring of their final year of elementary school. The previously established association between sexual abuse and earlier onset of maturation and earlier age at menarche was replicated, and in addition, physical abuse was found to be related to a more rapid tempo of pubertal development. A recent longitudinal study of 84 sexually abused girls and matched-comparison girls replicated the association between sexual abuse and earlier pubertal onset (including breast development and pubic hair; Noll et al., 2017 ). Further, using this same sample, childhood sexual abuse predicted earlier pubertal development which, in turn, was associated with higher levels of internalizing symptoms such as depression and anxiety concurrently and 2 years later ( Mendle et al., 2014 ). A third study with this sample found that earlier-maturing girls were more anxious in the pre- and peri-menarche periods than their later-maturing peers; however, their anxiety declined after menarche, suggesting a time-limited effect on mental health and the potential for recovery upon completion of pubertal maturation, as girls enter later adolescence ( Natsuaki et al., 2011 ).

The association between sexual abuse and earlier pubertal development was recently replicated using a large population-based sample of adolescents, the National Longitudinal Study of Adolescent Health 3 ( N = 6,273 girls). In that study, child sexual abuse predicted earlier menarche and development of secondary sexual characteristics, whereas other types of maltreatment did not ( Mendle et al., 2016 ). The distinctive role for early pubertal timing suggests that the heightened sexual circumstances of puberty may be especially challenging for girls whose lives have already been disrupted by adverse early experiences, yet also suggests a potential opportunity for intervention and resilience, particularly in later adolescence, once pubertal development is complete. However, the vast majority of research in this area has focused solely on girls, and we know very little about whether maltreatment is also associated with earlier pubertal timing in boys.

Other Family and Health Factors

Other family factors that may be stress-inducing yet much less extreme than maltreatment have also been associated with pubertal timing and tempo. For example, Quinlan (2003) found that the number of caretaking transitions a child experiences was associated with earlier menarche. Sung and colleagues (2016) found that exposure to greater parental harshness (but not unpredictability) during the first 5 years of life predicted earlier menarche; and a recent meta-analysis found that father absence was significantly related to earlier menarche ( Webster et al., 2014 ), although genetic confounding may play a role in this association ( Barbaro et al., 2017 ).

Health factors that may affect the metabolic system are also predictive of pubertal timing. For example, in girls, low birth weight ( Belsky et al., 2007 ) and obesity/higher body mass index (BMI) ( Wagner et al., 2015 ) have both been associated with earlier pubertal maturation. For boys, overweight (BMI ≥ 85th and < 95th percentile) has been associated with earlier pubertal maturation, whereas obesity (BMI ≥ 95th percentile) was associated with later pubertal maturation ( Lee et al., 2016 ), suggesting a complex association between aspects of the metabolic system and puberty in boys.

Environmental Exposures

Recently, researchers have examined whether a child's exposure to chemicals is related to pubertal maturation by serving as an endocrine disruptor (see e.g., Lomniczi et al., 2013 ; Simonneaux et al., 2013 ; Steingraber, 2007 ). In the first longitudinal study of age of pubertal timing and exposure to persistent organic pollutants—chemicals used in flame retardants—researchers found that the age at pubertal transition was consistently older in participants who were found to have higher chemical concentrations in collected blood samples ( Windham et al., 2015 ). The effects of neuroendocrine disruptors on girls' pubertal timing may begin during the prenatal period, as there is evidence that female reproductive development is affected by phthalate or bisphenol A exposure during specific critical periods of development in the mother's uterus ( Watkins et al., 2017 ).

Accelerated Maturation and Adaptive Plasticity

It is clear that early experiences can factor into accelerated pubertal timing and tempo, and theorists suggest that this may be adaptive. According to Mendle and colleagues (2011, p. 8) , “age at certain stressful life transitions represents a dose-response relationship with maturation, with earlier ages at these events associated with earlier development (e.g., Ellis and Garber, 2000 ).” Belsky et al. (1991) posited that children who are raised in harsh, stressful environments may have accelerated pubertal development to compensate for a mistrust of commitment and of investment in social relationships. According to Belsky and colleagues, early pubertal timing may serve the evolutionary biological purpose of elongating the window for reproductivity and fertility, to permit more conceptions in a lifetime. Thus, the well-documented association between adverse early life experiences and early pubertal development may itself be an adaptive response, one that reflects the plasticity in neurobiological systems during adolescence to adapt to the specific socio-cultural context.

The Social Context of Pubertal Maturation

Despite the role that stressful early life events play in accelerating pubertal timing, it is important to note that adolescence is also a period of potential for recovery. Even when an adolescent has experienced early adversity and this has precipitated earlier pubertal maturation, the social context in which that adolescent is developing can ultimately change the trajectory of their outcomes—for better or worse. For example, closer and less conflict-laden parent-child relationships can reduce associations between pubertal maturation and behavior problems, while more conflict-laden and less close relationships exacerbate them ( Booth et al., 2003 ; Dorn et al., 2009 ; Fang et al., 2009 ). Parental knowledge of an adolescent child's whereabouts and activities also plays a role, as the influence of pubertal timing on problematic outcomes is weakened when such parental knowledge of adolescent whereabouts and activities is high, and it is amplified when knowledge is low ( Marceau et al., 2015 ; Westling et al., 2008 ). During early childhood, a secure infant-mother attachment can buffer girls from the later effects of harsh environments on earlier pubertal maturation ( Sung et al., 2016 ).

The Context of Biological Sex and Gender Norms

The biological changes of puberty take place in social and cultural contexts, and these dynamic person-context interactions have implications for adolescent development. For instance, the physical changes associated with pubertal maturation affect an adolescent's self-image as much as the way he or she is treated and responded to by others ( Graber et al., 2010 ), and culturally grounded gender norms may make these associations more salient for girls than boys. Indeed, in the United States, although menstruation is acknowledged as a normal biological event, it is nevertheless often accompanied by feelings of shame and the need to conceal it from others, particularly males ( Stubbs, 2008 ). As a result, the arrival of a girl's first menstrual cycle is often accompanied by embarrassment and ambivalence ( Brooks-Gunn et al., 1994 ; Moore, 1995 ; Tang et al., 2003 ), as well as by negative feelings ( Rembeck et al., 2006 ), including anxiety, surprise, dismay, panic, and confusion ( Brooks-Gunn and Ruble, 1982 ; Ruble and Brooks-Gunn, 1982 ).

The arrival of puberty has other social consequences, such as changing dynamics and maturing relationships with parents, siblings, and peers, as well as the emergence of peer relationships with adults. Pubertal maturation is associated with a higher incidence of sexual harassment, both by peers of the same gender and across genders ( McMasters et al., 2002 ; Petersen and Hyde, 2009 ; Stattin and Magnusson, 1990 ). Social consequences may be exacerbated among youth experiencing early pubertal timing.

The increase in pubertal hormones (e.g., estradiol, progesterone, testosterone, dehydroepiandrosterone) and the changes they drive, such as the emergence of secondary sex characteristics, is also associated with the development of substance use ( Auchus and Rainey, 2004 ; Grumbach, 2002 ; Grumbach and Styne, 2003 ; Havelock et al., 2004 ; Matchock et al., 2007 ; Oberfield et al., 1990 ; Terasawa and Fernandez, 2001 ; Young and Altemus, 2004 ). At the same time, the causal direction of these findings is somewhat mixed ( Castellanos-Ryan et al., 2013 ; Dawes et al., 1999 ; Marceau et al., 2015 ), with variation by sex. In girls, relatively early pubertal timing and faster pubertal tempo often mark an increased risk for adolescent substance use ( Cance et al., 2013 ; Castellanos-Ryan et al., 2013 ; Costello et al., 2007 ; Lee et al., 2014 ). By contrast, in boys later pubertal timing and/or slower pubertal tempo mark an increased risk for substance use ( Davis et al., 2015 ; Marceau et al., 2015 ; Mendle and Ferrero, 2012 ). This striking gender difference in associations between pubertal maturation and substance use highlights how the same biological event (pubertal maturation) can lead to very different outcomes as a function of one's biological sex.

Puberty and Stress Sensitivity

Puberty-related hormones influence the way adolescents adjust to their environment, for example by experiencing symptoms of depression and anxiety. One mechanism through which this might occur is in pubertal hormones' ability to alter sensitivity to stress, making adolescent girls particularly sensitive to exogenous stressors. Recent studies using salivary cortisol as an index of stress regulation have documented heightened stress reactivity and delayed post-stress recovery in pubescent adolescents ( Gunnar, et al., 2009 ; Stroud et al., 2004 ; Walker et al., 2004 ). Cortisol is a steroid hormone released by the HPA axis, and disruption to this axis has been implicated in the development of symptoms of depression and anxiety (e.g., Gold and Chrousos, 2002 ; Guerry and Hastings, 2011 ; Sapolsky, 2000 ).

In fact, cortisol secretion is closely intertwined with age, puberty, and sex, which together appear to contribute to adolescent girls' vulnerability to external stressors ( Walker et al., 2004 ; Young and Altemus, 2004 ). As will be discussed in Chapter 3 , cortisol, along with neuroendocrine, autonomic, immune, and metabolic mediators, usually promotes positive adaptation in the body and the brain, such as efficient operation of the stress response system. However, when cortisol is over- or under-produced it can, along with the other mediators, produce negative effects on the body and brain, such as forming insulin resistance and remodeling the brain circuits that alter mood and behavior. At the same time, as will be shown in Chapter 3 , interventions during adolescence have the potential to mediate the harmful effects of stress.

In summary, puberty is shaped by both biological and social processes. Biologically, puberty occurs over an extended period during which neuroendocrine alterations result in the maturation of primary and secondary sex characteristics and the acquisition of reproductive maturity. The timing and tempo of pubertal development varies greatly, and the age at which an adolescent matures depends upon a combination of genetic and environmental influences, including early life experiences. Socially, pubertal maturation and its accompanying physical changes affect how adolescents perceive themselves and how they are treated by others, and early pubertal timing especially has been shown to have social consequences. While we know a great deal about the biological processes of puberty, much of the research, particularly on the role of adverse early experiences, is based on studies of girls rather than boys and excludes transgender and gender-nonconforming youth. Thus, it is important to monitor whether or not conclusions drawn from the extant research are relevant for both girls and boys, and to consider how further study of puberty in boys, transgender youth, and gender-nonconforming youth may deepen our understanding of these dynamic processes.

Despite this limitation, research on associations between stress exposure and pubertal timing and tempo makes clear the importance of early experiences and highlights the role of social determinants of health. Stressful living conditions are related to earlier pubertal timing and accelerated pubertal tempo. While early puberty may be an evolutionarily adaptive response to context that reflects neurobiological plasticity, there are important consequences that suggest it may not be adaptive in terms of supporting a long-term path to health and well-being for youth living in the 21st century. Structural changes that disrupt the systemic factors that increase risk for early puberty (e.g., resource deprivation) as well as supportive relationships can mitigate the risks associated with early puberty, can foster positive outcomes, and may promote adolescents' capability for resilience.

NEUROBIOLOGICAL DEVELOPMENT

Adolescence is a particularly dynamic period of brain development, second only to infancy in the extent and significance of the neural changes that occur. The nature of these changes—in brain structures, functions, and connectivity—allows for a remarkable amount of developmental plasticity unique to this period of life, making adolescents amenable to change. 4 These normative developments are required to prepare the brain so it can respond to the demands and challenges of adolescence and adulthood, but they may also increase vulnerability for risk behavior and psychopathology ( Paus et al., 2008 ; Rudolph et al., 2017 ). To understand how to take advantage of this versatile adolescent period, it is first important to recognize how and where the dynamic changes in the brain are taking place; Figure 2-2 shows structures and regions of the brain that have been the focus of adolescent developmental neuroscience.

Brain areas important to adolescent development. SOURCE: iStock.com/James Kopp.

In the following sections, we summarize current research on structural and functional brain changes taking place over the course of adolescence. Our summary begins with a focus on morphological changes in gray and white matter, followed by a discussion of structural changes in regions of the brain that have particular relevance for adolescent cognitive and social functioning. We then discuss current theoretical perspectives that attempt to account for the associations between neurobiological, psychological, and behavioral development in adolescence.

Notably, the field of adolescent neuroscience has grown quickly over the past several decades. Advances in technology continue to provide new insights into neurobiological development; however, there is still a lack of agreed-upon best practices, and different approaches (e.g., in equipment, in statistical modeling) can result in different findings ( Vijayakumar et al., 2018 ). Our summary relies on the most recent evidence available and, per the committee's charge, we focus on neurobiological changes that make adolescence a period of unique opportunity for positive development. This is not intended to be an exhaustive review of the literature; moreover, studies tend to use “typically” developing adolescents, which limits our ability to comment on whether or how these processes may change for young people with developmental delays or across a broader spectrum of neurodiversity.

High Plasticity Marks the Window of Opportunity

Studies of adolescent brain development have traditionally focused on two important processes: changes in gray matter and changes in myelin. Gray matter is comprised of neural cell bodies (i.e., the location of each nerve cell's nucleus), dendrites, and all the synapses, which are the connections between neurons. Thus, increases or decreases in gray matter reflect changes in these elements, representing, for instance, the formation or disappearance of synapsis (also known as “synaptogenesis” and “synaptic pruning”). New learning and memories are stored in dynamic synaptic networks that depend equally on synapse elimination and synapse formation. That is, unused connections and cells must be pruned away as the brain matures, specializes, and tailors itself to its environment ( Ismail et al., 2017 ).

White matter, on the other hand, is comprised of myelin. Myelin is the fatty sheath around the long projections, or axons, that neurons use to communicate with other neurons. The fatty myelin insulates the axonal “wire” so that the signal that travels down it can travel up to 100 times faster than it can on unmyelinated axons ( Giedd, 2015 ). With myelination, neurons are also able to recover quickly from firing each signal and are thereby able to increase the frequency of information transmission ( Giedd, 2015 ). Not only that, myelinated neurons can more efficiently integrate information from other input neurons and better coordinate their signaling, firing an outgoing signal only when information from all other incoming neurons is timed correctly ( Giedd, 2015 ). Thus, the increase in white matter is representative of the increase in quality and speed of neuron-to-neuron communication throughout adolescence. This is comparable to upgrading from driving alone on a single-lane dirt road to driving on an eight-lane paved expressway within an organized transportation/transit authority system, since it increases not only the amount of information trafficked throughout the brain but also the brain's computational power by creating more efficient connections.

Recent advances in neuroimaging methods have greatly enhanced our understanding of adolescent brain development over the past three decades. In the mid-2000s developmental neuroscientists described differential changes in gray matter (i.e., neurons) and white matter (i.e., myelin) over the course of adolescence. Specifically, gray-matter volume was believed to follow an inverted-U shape, peaking in different regions at different ages and declining over the course of late adolescence and adulthood ( Lenroot and Giedd, 2006 ). In contrast, cortical white matter, which reflects myelin growth, was shown to increase steadily throughout adolescence and into early adulthood, reflecting increased connectivity among brain regions ( Lenroot and Giedd, 2006 ). The proliferation of neuroimaging studies, particularly longitudinal studies following children over the course of adolescence, has enabled researchers to examine these processes in more detail and across a larger number of participants ( Vijayakumar et al., 2018 ).

Analyses of about 850 brain scans from four samples of participants ranging in age from 7 to 29 years (average = 15.2 years) confirm some previous trends, disconfirm others, and highlight the complexity in patterns of change over time. Researchers found that gray-matter volume was highest in childhood, decreased across early and middle adolescence, and began to stabilize in the early twenties; this pattern held even after accounting for intracranial and whole brain volume ( Mills et al., 2016 ). Additional studies of cortical volume have also documented the highest levels occurring in childhood with decreases from late childhood throughout adolescence; the decrease appears to be due to the thinning of the cortex ( Tamnes et al., 2017 ). Importantly, this finding contrasts with the “inverted-U shape” description of changes in gray-matter volume and disconfirms previous findings of a peak during the onset of puberty ( Mills et al., 2016 ).

For white-matter volume, on the other hand, researchers found that across samples, increases in white-matter volume occurred from childhood through mid-adolescence and showed some stabilizing in late adolescence ( Mills et al., 2016 ). This finding generally confirms patterns observed in other recent studies, with the exception that some researchers have found continued increases in white-matter volume into early adulthood (versus stabilizing in late adolescence; e.g., Aubert-Broche et al., 2013 ). Figure 2-3 shows these recent findings related to gray and white matter.

Cortical gray- and white-matter volume, ages 5 to 30. NOTES: Age in years is measured along the x-axis and brain measure along the y-axis (raw values (mm 3 ). Best fitting models are represented by the solid lines. Dashed lines represent 95-percent confidence (more...)

The widely held belief about a peak in cortical gray matter around puberty followed by declines throughout adolescence was based on the best available evidence at the time. New studies show steady declines in cortical volume beginning in late childhood and continuing through middle adolescence. While the decrease in volume is largely due to cortical thinning rather than changes in surface area, there appear to be complex, regionally specific associations between cortical thickness and surface area that change over the course of adolescence ( Tamnes et al., 2017 ). Discrepant findings can be attributed to a number of factors including head motion during brain imaging procedures (more common among younger participants), different brain imaging equipment, and different approaches to statistical modeling ( Tamnes et al., 2017 ; Vijayakumar et al., 2018 ). There do appear to be converging findings regarding overall directions of change; however, inconsistencies in descriptions of trajectories, peaks, and regional changes will likely continue to emerge as researchers work toward agreed-upon best practices ( Vijayakumar et al., 2018 ). Importantly, though, as Mills and colleagues (2016, p. 279) point out, it is critical to acknowledge that “it is not possible to directly relate developmental changes in morphometric MRI measures to changes in cellular or synaptic anatomy” (also see Mills and Tamnes, 2014 ). In other words, patterns of change in overall gray- or white-matter volume do not provide insight into the specific ways in which neural connections (e.g., synapses, neural networks) may change within the adolescent brain.

In fact, some neural circuity, consisting of networks of synaptic connections, is extremely malleable during adolescence, as connections form and reform in response to a variety of novel experiences and stressors ( Ismail et al., 2017 ; Selemon, 2013 ). Gray-matter reduction in the cortex is associated with white-matter organization, indicating that cortical thinning seen in adulthood may be a result of both increased connectivity of necessary circuitry and pruning of unnecessary synapses ( Vandekar et al., 2015 ). Thus, adolescent brains can modulate the strength and quality of neuronal connections rapidly to allow for flexibility in reasoning and for leaps in cognition ( Giedd, 2015 ).

Structural Changes in the Adolescent Brain

Two key neurodevelopmental processes are most reliably observed during adolescence. First, there is evidence of significant change and maturation in regions of the prefrontal cortex (PFC) involved in executive functioning and cognitive and impulse control capabilities ( Crone and Steinbeis, 2017 ; Steinberg, 2005 ). In other words, areas of the brain that support planning and decision-making develop significantly during the second decade of life. Second, there is evidence of improved connectivity 5 within and between the cortical (i.e., outer) and subcortical (i.e., inner) regions of the brain. Moreover, in both the cortical and subcortical regions, there are age-related and hormone-related changes in neural activity and structure, such as increased volume and connectivity ( Gogtay et al., 2004 ; Østby et al., 2009 ; Peper and Dahl, 2013 ; Wierenga et al., 2014 ).

Over the course of adolescence, regions of the PFC undergo protracted development and significant remodeling. Cortical circuits, especially those that inhibit behavior, continue to develop, enhancing adolescents' capacity for self-regulation ( Caballero and Tseng, 2016 ). Compared to adults, adolescents have a significantly less mature cortical system and tend to utilize these regions less efficiently, and this impacts their top-down cognitive abilities including planning, working memory, impulsivity control, and decision-making ( Casey and Caudle, 2013 ). Ongoing development of structures and connections within the cortical regions corresponds to more efficient balancing of inputs and outputs as adolescents interact with the world.

Changes within subcortical brain regions are also reflected in adolescent capabilities. For instance, increased volume in certain subregions of the hippocampus may predict greater capacity for memory recall and retention in adolescents ( Tamnes et al., 2014 ). Adolescents also display heightened activity in the hippocampus, compared with adults, and differential reward processing in the striatum, which is part of the basal ganglia and plays an important role in motivation and perception of reward. This neural activity may explain their increased sensitivity to rewards and contribute to their greater capacity for learning and habit formation, particularly when incentivized by positive outcomes ( Davidow et al., 2016 ; Sturman and Moghaddam, 2012).

Another subcortical structure, the amygdala, undergoes significant development during puberty and gains new connections to other parts of the brain, such as the striatum and hippocampus ( Scherf et al., 2013 ). The amygdala modulates and integrates emotional responses based on their relevance and impact in context. In conjunction with the amygdala's substantial development, adolescents show higher amygdala activity in response to threat cues 6 than do children or adults ( Fuhrmann et al., 2015 ; Hare et al., 2008 ; Pattwell et al., 2012 ). Consequently, they are prone to impulsive action in response to potential threats 7 ( Dreyfuss et al., 2014 ). Changes in the hippocampus and amygdala may be responsible for suppressing fear responses in certain contexts ( Pattwell et al., 2011 ). Such fearlessness can be adaptive for adolescents as they explore new environments and make important transitions—such as entering college or starting a new job away from home. Children and adults do not tend to show the same kind of fear suppression as adolescents, suggesting that this is unique to this stage of development ( Pattwell et al., 2011 ).

A Neurodevelopmental Perspective on Risk-Taking

In recent years, researchers have worked to reconcile contemporary neuroscience findings with decades of behavioral research on adolescents. There has been a particular emphasis on understanding “risky” behavior through the lens of developmental neuroscience. Risk-taking can be driven by a tendency for sensation-seeking, in which individuals exhibit an increased attraction toward novel and intense sensations and experiences despite their possible risks ( Steinberg, 2008 ; Zuckerman and Kuhlman, 2000 ). This characteristic is heightened during adolescence and is strongly associated with reward sensitivity and drive ( Cservenka et al., 2013 ) as well as the rise in dopamine pathways from the subcortical striatum to the PFC ( Wahlstrom et al., 2010 ). Ironically, as executive function improves, risk-taking based on sensation-seeking also rises, likely due to these strengthened dopamine pathways from the striatum to the PFC regions ( Murty et al., 2016 ; Wahlstrom et al., 2010 ). Despite these stronger sensation-seeking tendencies, however, by mid-adolescence most youth are able to perform cognitive-control tasks at the same level as adults, signaling their capacity for executive self-control ( Crone and Dahl, 2012 ).

Risk-taking can also be driven by impulsivity, which includes the tendency to act without thinking about consequences (impulsive action) or to choose small, immediate rewards over larger, delayed rewards (impulsive choice) ( Romer et al., 2017 ). Impulsive action, which is based on insensitivity to risk, is a form of risk-taking that peaks during early adolescence and is inversely related to working memory ability ( Romer et al., 2011 ). It may also be a consequence of asynchronous limbic-PFC maturation, which is described below. Notably, impulsive actions are seen most frequently in a subgroup of adolescents with pre-existing impairment in self-control and executive function ( Bjork and Pardini, 2015 ). In contrast, impulsive choice behaviors, which are made under conditions of known risks and rewards, do not peak in adolescence. Instead, impulsive choice declines from childhood to adulthood, reflecting the trend of increasing, prefrontal-regulated executive functions throughout adolescence ( van den Bos et al., 2015 ). Interestingly, when given the choice between two risky options with ambiguous reward guarantees, adolescents are more inclined to explore the riskier option than are adults ( Levin and Hart, 2003 ), showing a greater tolerance for ambiguities in reward and stronger exploratory drive ( Tymula et al., 2012 ).

Theoretical models have emerged to explain how neurobiological changes map onto normative “risk” behaviors in adolescence. While some argue that these models and accompanying metaphors may be overly simplistic (e.g., Pfeifer and Allen, 2012 ), the models are nevertheless utilized frequently to guide and interpret research (e.g., Steinberg et al., 2018 ). We briefly discuss two of them here: the “dual systems” model and the “imbalance” model.

The “dual systems” model ( Shulman et al., 2016 ; Steinberg, 2008 ) represents “the product of a developmental asynchrony between an easily aroused reward system, which inclines adolescents toward sensation seeking, and still maturing self-regulatory regions, which limit the young person's ability to resist these inclinations” ( Steinberg et al., 2018 ). The “reward system” references subcortical structures, while the “self-regulatory regions” refer to areas like the PFC. Proponents of the dual-systems model point to recent findings on sensation seeking and self-regulation from a study of more than 5,000 young people spanning ages 10 to 30 across 11 countries. A similar pattern emerged across these settings. In 7 of 11 countries there was a peak in sensation seeking in mid-to-late adolescence (around age 19) followed by a decline. Additionally, there was a steady rise in self-regulation during adolescence; self-regulation peaked in the mid-20s in four countries and continued to rise in five others. The researchers note that there were more similarities than differences across countries and suggest that the findings provide strong support for a dual-systems account of sensation seeking and self-regulation in adolescence.

A second model, the “imbalance” model, shifts the focus away from an orthogonal, dual systems account and instead emphasizes patterns of change in neural circuitry across adolescence. This fine-tuning of circuits is hypothesized to occur in a cascading fashion, beginning within subcortical regions (such as those within the limbic system), then strengthening across regions, and finally occurring within outer areas of the brain like the PFC ( Casey et al., 2016 ). This model corresponds with observed behavioral and emotional regulation—over time, most adolescents become more goal-oriented and purposeful, and less impulsive ( Casey, 2015 ). Proponents of the imbalance model argue that it emphasizes the “dynamic and hierarchical development of brain circuitry to explain changes in behavior throughout adolescence” ( Casey et al., 2016 , p. 129). Moreover, they note that research stemming from this model focuses less on studying specific regions of the brain and more on how information flows within and between neural circuits, as well as how this flow of information shifts over the course of development (e.g., “temporal changes in functional connectivity within and between brain circuits,” p. 129).

Rethinking the “Mismatch” Between the Emotional and Rational Brain Systems

Regardless of whether one of these two models more accurately represents connections between adolescent neurobiological development and behavior, both perspectives converge on the same point: fundamental areas of the brain undergo asynchronous development throughout adolescence. Moreover, adolescent behavior, especially concerning increased risk-taking and still-developing self-control, has been notably attributed to asynchronous development within and between subcortical and cortical regions of the brain. The former drives emotion, and the latter acts as the control center for long-term planning, consideration of outcomes, and level-headed regulation of behavior ( Galván et al., 2006 ; Galván, 2010 ; Mueller et al., 2017 ; Steinbeis and Crone, 2016 ). Thus, if connections within the limbic system develop faster than those within and between the PFC region, 8 the imbalance may favor a tendency toward heightened sensitivity to peer influence, impulsivity, risk-taking behaviors, and emotional volatility ( Casey and Caudle, 2013 ; Giedd, 2015 ; Mills et al., 2014 ).

Indeed, adolescents are more impulsive in response to positive incentives than children or adults, although they can suppress these impulses when large rewards are at stake. Adolescents are also more sensitive than children or adults to the presence of peers and to other environmental cues, and show a heightened limbic response to threats ( Casey, 2015 ). As the cortical regions continue to develop and activity within and across brain regions becomes more synchronized, adolescents gain the capacity to make rational, goal-directed decisions across contexts and conditions.

The idea of asynchrony or “mismatch” between the pace of subcortical development and cortical development implies that these developmental capacities are nonoptimal. Yet, even though they are associated with impulsivity and risk-taking, we should not jump to the conclusion that the gap in maturation between the emotion and control centers of the brain is without developmental benefit. As Casey (2015, p. 310) notes, “At first glance, suggesting that a propensity toward motivational or emotional cues during adolescence is adaptive may seem untenable. However, a heightened activation into action by environmental cues and decreased apparent fear of novel environments during this time may facilitate evolutionarily appropriate exploratory behavior.” While an adolescent's “heart over mind” mentality may compromise judgment and facilitate unhealthy behaviors, it can also spawn creativity and exploration. Novelty seeking can be a boon to adolescents, spurring them to pursue exciting, new directions in life ( Spear, 2013 ).

If properly monitored and cushioned by parents and the community, adolescents can learn from missteps and take advantage of what can be viewed as developmental opportunities . Indeed, because adolescents are more sensitive to rewards and their decision-making ability may skew more toward seeking the positive benefits of a choice and less toward avoiding potential risks, this tendency can enhance learning and drive curiosity ( Davidow et al., 2016 ). To avoid stereotyping all adolescents as “underdeveloped” or “imbalanced,” it is important to recognize the nuances in the different types of risk-taking behavior and to counterbalance a focus on negative outcomes by observing the connections between risk-taking and exploration, curiosity, and other attributes of healthy development ( Romer et al., 2017 ).

The “mismatch” model provides one way of understanding adolescents' capacity for self-control and involvement in risky behavior. A better model of adolescent neurobiological development, some argue, is a “lifespan wisdom model,” prioritizing the significance of experience on brain maturation that can only be gained through exploration ( Romer et al., 2017 ). Indeed, growing evidence shows that adolescents have a distinctive ability for social and emotional processing that allows them to adapt readily to the capricious social contexts of adolescence, and equips them with flexibility in adjusting their motivations and prioritizing new goals ( Crone and Dahl, 2012 ; Nigg and Nagel, 2016 ).

Despite differences between neurobiological models, there is agreement that distinctions between adolescent and adult behaviors necessitate policies and opportunities intended to address adolescent-specific issues. With their heightened neurocognitive capacity for change, adolescents are in a place of both great opportunity and vulnerability. Key interventions during this period may be able to ameliorate the impact of negative experiences earlier in life, providing many adolescents with a pivotal second chance to achieve their full potential and lead meaningful, healthy, and successful lives ( Guyer et al., 2016 ; see also Chapter 3 ).

Cognitive Correlates of Adolescent Brain Development

Reflective of the ongoing changes in the brain described above, most teens become more efficient at processing information, learning, and reasoning over the course of adolescence ( Byrnes, 2003 ; Kuhn, 2006 , 2009 ). The integration of brain regions also facilitates what is called “cognitive control,” the ability to think and plan rather than acting impulsively ( Casey, 2015 ; Casey et al., 2016 ; Steinberg, 2014 ).

Changes in components of cognitive control, such as response selection/inhibition and goal selection/maintenance, along with closely associated constructs such as working memory, increase an individual's capacity for self-regulation of affect and behavior ( Ochsner and Gross, 2005 ). Importantly, each of these aspects of cognitive control appears to have distinct developmental trajectories, and each may be most prominently associated with distinct underlying regions of the cortex ( Crone and Steinbeis, 2017 ). For example, although the greatest developmental improvements in response inhibition and interference control may be observed prior to adolescence, improvements in flexibility, error monitoring, and working memory are more likely to occur throughout the second decade of life ( Crone and Steinbeis, 2017 ). This suggests different developmental trajectories, whereby more basic, stimulus-driven cognitive control processes develop earlier than do more complex cognitive control processes, which rely on internal and abstract representation ( Crone and Steinbeis, 2017 ; Dumontheil et al., 2008 ).

Those functions that do continue to show significant developmental change during adolescence seem to especially rely on the capacity for abstract representation, which is a capacity that has been found to undergo a distinctive increase during adolescence ( Dumontheil, 2014 ). The capacity for abstract representation can relate to both temporal and relational processes, that is, to both long-term goals and to past or future events (temporal) and to representing higher-order relationships between representations (relational) as distinct from simple stimulus features ( Dumontheil, 2014 ). From early through late adolescence (into adulthood), this increase in abstract thinking ability makes teens better at using evidence to draw conclusions, although they still have a tendency to generalize based on personal experience—something even adults do. Adolescents also develop greater capacity for strategic problem-solving, deductive reasoning, and information processing, due in part to their ability to reason about ideas that may be abstract or untrue; however, these skills require scaffolding and opportunities for practice ( Kuhn, 2009 ).

Recent research on cognitive development during adolescence has focused on both cognitive and emotional (or “affective”) processing, particularly to understand how these processes interact with and influence each other in the context of adolescent decision making. First, the capacity for abstract representation and for affective engagement with such representations ( Davey et al., 2008 ) increases the capacity for self-regulation of emotions in order to achieve a goal ( Ochsner and Gross, 2005 ). Indeed, the capacity to regulate a potent, stimulus-driven, short-term response may rely on the ability to mentally represent and affectively engage with a longer-term goal. Furthermore, such stimulus-driven, affective influences on cognitive processing, including on decision making, risk-taking, and judgment, change significantly over the course of adolescence ( Hartley and Somerville, 2015 ; Steinberg, 2005 ).

Beyond individual capacities for cognitive regulation, the social and emotional context for cognitive processing matters a great deal. The presence of peers and the value of performing a task influence how motivating certain contexts may be and the extent to which cognitive processing is recruited ( Johnson et al., 2009 ). Moreover, there is increasing evidence that some of these changes in cognitive and affective processing are linked to the onset of puberty ( Crone and Dahl, 2012 ). Researchers have found that adolescents do better than young adults on learning and memory tasks when the reward systems of the brain are engaged ( Davidow et al., 2016 ).

These changes in cognitive functioning may have adaptive qualities as part of normative adolescent development, even though they also make some individuals more vulnerable to psychopathology, such as depression and anxiety disorders. Notably, the flexibility of the frontal cortical network may be greater in adolescence than in adulthood ( Jolles and Crone, 2012 ). Such flexibility may result in an improved ability to learn to navigate the increasingly complex social challenges that are part of adolescents' social worlds, and as adolescents encounter increasing opportunities for autonomy it may prove to be adaptive. In addition, the ability to shift focus in a highly motivated way could allow more learning, problem solving, and use of creativity ( Kleibeuker et al., 2016 ). Of particular relevance, such emerging abilities may also determine the degree to which an individual can take advantage of new learning opportunities, including mental health–promoting interventions. With the right supports, this capacity for flexibility and adaptability can foster deep learning, complex problem-solving skills, and creativity ( Crone and Dahl, 2012 ; Hauser et al., 2015 ; Kleibeuker et al., 2012 ).

The extensive neurobiological changes in adolescence enable us to reimagine this period as one of remarkable opportunity for growth. Connections within and between brain regions become stronger and more efficient, and unused connections are pruned away. Such developmental plasticity means adolescents' brains are adaptive; they become more specialized in response to environmental demands. The timing and location of the dynamic changes are also important to understand. The onset of puberty, often between ages 10 and 12, brings about changes in the limbic system region resulting in increased sensitivity to both rewards and threats, to novelty, and to peers. In contrast, it takes longer for the cortical regions, implicated in cognitive control and self-regulation, to develop ( Steinberg et al., 2018 ).

Adolescent brains are neither simply “advanced” child brains, nor are they “immature” adult brains—they are specially tailored to meet the needs of this stage of life ( Giedd, 2015 ). Indeed, the temporal discrepancy in the specialization of and connections between cortical and subcortical brain regions makes adolescence unique. The developmental changes heighten sensitivity to reward, willingness to take risks, and the salience of social status, propensities that are necessary for exploring new environments and building nonfamilial relationships. Adolescents must explore and take risks to build the cognitive, social, and emotional skills they will need to be productive adults. Moreover, the unique and dynamic patterns of brain development in adolescence foster flexible problem-solving and learning ( Crone and Dahl, 2012 ). Indeed, adolescence is a seminal period for social and motivational learning ( Fuligni, 2018 ), and this flexibility confers opportunity for adaptability and innovation.

While developmental plasticity in adolescence bears many advantages, as with all aspects of development the environment matters a great deal. The malleable brains of adolescents are not only adaptable to innovation and learning but also vulnerable to toxic experiences, such as resource deprivation, harsh, coercive or antisocial relationships, and exposure to drugs or violence. All of these can “get under the skin” as adolescents develop, or more precisely interact with the brain and body to influence development (see Chapter 3 ).

What is more, the majority of mental illnesses—including psychotic and substance use disorders—begin by age 24 ( Casey, 2015 ; Giedd, 2015 ). This means that we have a collective responsibility to ask, “How can we create the kinds of settings and supports needed to optimize development during this period of life?” This goes well beyond simply keeping youth out of harm's way, and instead signals an urgent need to consider how we design the systems with which adolescents engage most frequently to meet their developmental needs. Notably, scholars studying adolescent developmental neuroscience suggest the next generation of research should consider questions that shift from understanding risk to understanding thriving, and context-specific opportunities to promote it. Such questions for the field include, “How does brain development create unique opportunities for learning and problem solving?,” “Is the adolescent brain more sensitive to some features of the social environment than others?,” and “Are trajectories of change [in cognitive control and emotional processing] steeper or quicker during some periods than others, potentially providing key windows for input and intervention?” ( Fuligni et al., 2018 , p. 151).

PSYCHOSOCIAL DEVELOPMENT IN ADOLESCENCE

As described above, young people develop increased cognitive abilities throughout adolescence. These cognitive abilities provide the capacity for other aspects of psychosocial development that occur during the period. This section describes the psychosocial developmental tasks—including developing identity and a capacity for self-direction—that adolescents complete during their transition to adulthood. Understanding one's self, understanding one's place in the world, and understanding one's capacity to affect the world (i.e., agency) are all processes that begin to take shape during adolescence in tandem with the physiological, neurobiological, and cognitive changes discussed above.

The trajectory of social and emotional development in adolescence may perhaps be best characterized as a time of increasing complexity and integration. As is true of their neurobiological development during the period, adolescents' capacity for understanding and engaging with self, others, and societal institutions requires both integration and deepening. It requires adolescents to integrate multiple perspectives and experiences across contexts, and also to deepen their ability to make sense of complex and abstract phenomena.

This section begins with a summary of developmental trends in adolescent self- and identity development at a broad level, followed by a brief discussion of how these trends reflect recent findings from developmental neuroscience. From there, we discuss group-specific social identities. While there are many critical dimensions of social identity (e.g., gender, social class, religion, immigration status, disability, and others), we use race and sexuality as exemplars given the recent, monumental shifts in racial/ethnic demographics and in the social and political climate around sexual minority status in the United States. The focus on race and sexuality is not intended to minimize other dimensions of identity; indeed, identity development is a salient process for all adolescents regardless of social group memberships. Moreover, as we discuss below, developmental scientists are increasingly calling for research that examines the intersectional nature of identities, both at the individual level as well as in ways that reflect membership in multiple groups that have historically experienced marginalization ( Santos and Toomey, 2018 ).

Finding an answer to the question, “Who am I?” is often viewed as a central task of adolescence. Decades ago, Erik Erikson (1968) argued that during adolescence, youth take on the challenge of developing a coherent, integrated, and stable sense of themselves, and that failing to do so may make the transition to adult roles and responsibilities more difficult. Erikson's concept of identity development assumes opportunities for exploration and choice and may or may not generalize across global contexts ( Arnett, 2015 ; Syed, 2017 ). However, it has utility in the United States, where societal structures and dominant values such as independence and individuality encourage identity exploration.

Closely related to the question, “Who am I?” is the question, “ How do I see myself?” ( Harter, 2012 ). McAdams (2013) describes the developmental trajectory of “self” using a set of sequential metaphors: the “social actor” in childhood (because children engage in action) grows to become a “motivated agent” in adolescence (because teens are more purposeful and agent-driven, guided by values, motives, and hopes), and finally an “autobiographical author” in emerging adulthood, a time when young people work on building a coherent self-narrative. Studies of youth across the span of adolescence show that, for many young people, the sense of self and identity become more integrated, coherent, and stable over time ( Harter, 2012 ; Klimstra et al., 2010 ; Meeus et al., 2010 ). Importantly, theory suggests and empirical evidence supports the idea that having a more “achieved” identity and integrated sense of self relates to positive well-being in adulthood and even throughout the life course (e.g., Kroger and Marcia, 2011 ; Meca et al., 2015 ; Schwartz et al., 2011 ).

While there is great variability across youth, there are also some distinct developmental trends in the emergence of self and identity. In early adolescence, young teens' self-definitions are increasingly differentiated relative to childhood. They see themselves in multiple ways across various social and relational contexts, for example one way when with their family and another way when with close friends in the classroom. Although a young adolescent may carry a great number of “abstractions” about his or her self, these labels tend to be fragmented and sometimes even contradictory ( Harter, 2012 ). For instance, a 13-year-old may view herself as shy and quiet in the classroom, as loud and bubbly with close friends, and as bossy and controlling with her younger siblings. Longitudinal studies suggest that some perceptions of self (e.g., academic self-concept) decline in early adolescence as youth transition to middle school; however, there is a great deal of individual variability, variability across domains (e.g., academic vs. behavioral self-concept), and variability by gender (higher athletic self-concept among males vs. females; Cole et al., 2001 ; Gentile et al., 2009 ).

In middle adolescence, teens may still hold onto multiple and disjointed abstractions of themselves; however, their growing cognitive abilities allow for more frequent comparisons among the inconsistencies, and heightened awareness of these contradictions can create some stress ( Brummelman and Thomaes, 2017 ; Harter, 2012 ). In this period, youth may also be more aware that their conflicting self-characterizations tend to occur most often across different relationship contexts. As in early adolescence, discrepancies between real and ideal selves can create stress for some youth, but as teens develop deeper meta-cognitive and self-reflection skills, they are better able to manage the discrepancies. To continue with the same hypothetical teen introduced above at age 13, at age 16 she might view being shy and quiet in the classroom and loud and bubbly with friends as parts of a more holistic, less fragmented sense of self.

Older adolescents have greater abilities to make sense of their multiple abstractions about self. They can reconcile what seem like contradictory behaviors by understanding them in context ( Harter, 2012 ). For instance, older teens are more likely to view their different patterns of behavior across settings as reflecting a positive trait like “flexibility,” or they may characterize themselves as “moody” if they vacillate between positive and negative emotions in different situations. While peers are still important in late adolescence, youth may rely on them less when making self-evaluations; they also have greater capacity for perspective-taking and attunement to others, especially in the context of supportive relationships.

Emerging adulthood provides additional opportunities for experimenting with vocational options, forming new friendships and romantic relationships, and exercising more independent decision-making ( Arnett, 2015 ; Harter, 2012 ; Schwartz et al., 2005 ). Many young adults shift from “grand” visions of possible selves to visions that are narrower and directly related to immediate opportunities. New experiences across contexts—like attending college or transitioning into the workforce—can shape whether emerging adults develop an authentic and integrated sense of self.

With the normative development of heightened sensitivity to social information, some youth may rely heavily on peer feedback in self-evaluation; however, parents still play an important role in supporting a positive sense of self, especially when they are attuned to youths' needs and couple their high expectations with support ( Harter, 2012 ). Indeed, secure and supportive relationships with parents can help early and middle adolescents develop a clear sense of self ( Becht et al., 2017 ) and can buffer youth who are socially anxious against harsh self-criticism ( Peter and Gazelle, 2017 ).

Identity and Self: A Neurobiological Perspective

Recent advances in developmental neuroscience appear to complement decades of behavioral research on youth. For instance, the integrated-circuitry model of adolescent brain development discussed in the previous section ( Casey et al., 2016 ), along with other models emphasizing the growing integration within and between emotionally sensitive brain regions (e.g., the limbic system) and those involved in planning and decision making (e.g., the cortical regions), correspond with the observation that adolescents develop a more coherent sense of self over time and experience. Likewise, changes observed in social and affective regions of the brain during adolescence align with behavioral tendencies toward exploration and trying new things ( Crone and Dahl, 2012 ; Flannery et al., 2018 ). Although the evidence base is still growing, recent studies document how self-evaluation and relational identity processes are linked with regions of the brain like the ventromedial PFC (vmPFC) (which plays a role in the inhibition of emotional responses, in decision making, and in self-control) and the rostral/perigenual anterior cingulate cortex (which plays a role in error and conflict detection processes). In particular, activity in these regions increases from childhood through adolescence in a manner consistent with changes in identity development ( Pfeifer and Berkman, 2018 ).

Recent theoretical models of value-based decision making suggest specific ways in which identity development and neural development are linked in adolescence ( Berkman et al., 2017 ; Pfeifer and Berkman, 2018 ). An important premise is that while adolescents may be more sensitive to social stimuli such as peer norms and to rewarding outcomes such as tangible gains, their sense of self is still a critical factor influencing their behavior. In other words, while social norms and tangible gains and costs represent some of the “value inputs,” their construal of self and identity are also factors in their decision making. Moreover, neural evidence, like the activation observed in the vmPFC during self- and relational identity tasks, suggests that identity and self-related processes may play a greater role in value-based decision making during adolescence than they do in childhood ( Pfeifer and Berkman, 2018 ).

Social Identities in Adolescence

As many youth work toward building a cohesive, integrated answer to the question, “Who am I?,” the answer itself is shaped by membership across multiple social identity groups: race, ethnicity, nationality, sexuality, gender, religion, political affiliation, ability status, and more. Indeed, in the context of increasingly complex cognitive abilities and social demands, youth may be more likely to contest, negotiate, elaborate upon, and internalize the meaning of membership in racial/ethnic, gender, sexual, and other social identity groups (e.g., Umaña-Taylor et al., 2014 ). From a developmental perspective, these tasks are paramount in a pluralistic, multiethnic and multicultural society like the United States, which, as discussed in Chapter 1 , is more diverse now than in previous generations.

Ethnic-Racial Identity. Currently, our nation's population of adolescents is continuing to increase in diversity, with no single racial or ethnic group in the majority. A burgeoning area of study over the past two decades concerns ethnic-racial identity (ERI), and research in this field has found that for most youth, particularly adolescents of color, ERI exploration, centrality, and group pride are positively related to psychosocial, academic, and even health outcomes ( Rivas-Drake et al., 2014 ). ERI is multidimensional—it includes youths' beliefs about their group and how their race or ethnicity relate to their self-definition—both of which may change over time ( Umaña-Taylor et al., 2014 ). For immigrant youth, developing their own ERI may involve an internal negotiation between their culture of origin and that of their new host country, and most immigrant youth show a great deal of flexibility in redefining their new identity ( Fuligni and Tsai, 2015 ). Regardless of country of origin, making sense of one's ERI is a normative developmental process that often begins in adolescence ( Williams et al., 2012 ). Indeed, given that research has consistently found ERI to be associated with adaptive outcomes, dimensions of ERI can be understood as components of positive youth development ( Williams et al., 2014 ).

Sexual Orientation and Gender Identity. One of the distinctive aspects of adolescence is the emergence and awareness of sexuality, and a related aspect is the emerging salience of gender roles and expression. Adolescence is also a time when identities or sense of self related to gender and sexuality are developed and solidified ( Tolman, 2011 ), and this occurs in a period during which sexuality and gender norms are learned and regulated by peers ( Galambos et al., 1990 ). In this developmental context, LGBTQ youth begin to understand their sexual and gender identities.

The growing societal acceptance and legal recognition of LGBTQ youth is implicated in the recent observed drop in the age at which most of these young people “come out,” that is, disclose their same-sex sexual identities. Less than a generation ago, LGBTQ people in the United States typically came out as young adults in their 20s; today the average age at coming out appears to be around 14, according to several independent studies ( Russell and Fish, 2017 ).

In the context of such changes and growing acceptance and support for LGBTQ youth developing their sexual identity, it might be expected that the longstanding health and behavior disparities between these adolescents and heterosexual and cis-gender adolescents would be lessening. Yet multiple recent studies challenge that conclusion. Things do not appear to be getting “better” for LGBTQ youth: rather than diminishing, health disparities across multiple domains appear to be stable if not widening ( Russell and Fish, 2017 ). This pattern may be explained by several factors, including greater visibility and associated stigma and victimization for LGBTQ youth, just at the developmental period during which youth engage in more peer regulation and bullying in general, especially regarding sexuality and gender ( Poteat and Russell, 2013 ). In fact, a meta-analysis of studies of homophobic bullying in schools showed higher levels of homophobic bullying in more recent studies ( Toomey and Russell, 2016 ). These patterns point to the importance of policies and programs that help schools, communities, and families understand and support LGBTQ (and all) youth (see Chapter 7 ).

Identity Complexity. Beyond race, gender, or sexuality alone, having a strong connection to some dimension of social identity—which could also be cultural, religious, or national—appears to be important for psychological well-being in adolescence ( Kiang et al., 2008 ). Recent research also suggests that young adolescents benefit from having a more complex, multifaceted identity that goes beyond stereotypical expectations of social-group norms, especially when it comes to inclusive beliefs ( Knifsend and Juvonen, 2013 ). For instance, a youth who identifies as a Black, 13-year-old, transgender female who plays volleyball and loves gaming is apt to have more positive attitudes toward other racial/ethnic groups than she would if she viewed racial/ethnic identity and other social identities as necessarily convergent (such as the notion that “playing volleyball and being a gamer are activities restricted to youth from specific racial/ethnic groups”; Knifsend and Juvonen, 2014 ).

However, context is still important, and the association between identity complexity and inclusive beliefs in early adolescence tends to be stronger for youth who have a diverse group of friends ( Knifsend and Juvonen, 2014 ). Among college-age students there is also variation by race and ethnicity. For instance, the positive association between having a complex social identity and holding more inclusive attitudes toward others has been found most consistently among students who are members of the racial/ethnic majority; for members of racial/ethnic minority groups, convergence between racial/ethnic identity and other in-group identities is not related to attitudes toward other racial/ethnic groups ( Brewer et al., 2013 ). Beyond outgroup attitudes, there is evidence that social identity complexity has implications for youths' own perceptions of belonging; for instance, Muslim immigrant adolescents (ages 15 to 18) with greater identity complexity reported a stronger sense of identification with their host country ( Verkuyten and Martinovic, 2012 ).

Social Identity and Neurobiology

Cultural neuroscience provides some insight into how social identity development may manifest at the neurobiological level, although there is still much work to be done to understand the deep associations between biology and culture ( Mrazek et al., 2015 ). In adolescence, evidence suggests, areas of the brain attuned to social information may be undergoing shifts that heighten youths' social sensitivity ( Blakemore and Mills, 2014 ), and of course, adolescents' “social brains” develop in a cultural context. For instance, we know the amygdala responds to stimuli with heightened emotional significance; in the United States, where negative stereotypes about Blacks contribute to implicit biases and fears about them, amygdala sensitivity to Black faces has been documented in adult samples ( Cunningham et al., 2004 ; Lieberman et al., 2005 ; Phelps et al., 2000 ).

In a study of children and adolescents (ages 4 to 16) in the United States, Telzer and colleagues (2013) found that amygdala activation in response to racial stimuli, such as images of Black faces, was greater in adolescence than during childhood. They suggest that identity processes reflecting heightened sensitivity to race, along with biological changes (e.g., those stemming from puberty) related to a “social reorientation” of the amygdala, may be among the mechanisms that explain these race-sensitive patterns of activation in adolescence ( Telzer et al., 2013 ). Importantly, neural activation appears to vary based on the context of social experiences. Specifically, the amygdala activation observed in response to Black faces was attenuated for youth who had more friends and schoolmates of a race differing from their own (i.e., cross-race friends).

The foregoing findings converge with psychobehavioral studies that demonstrate the importance of school and friendship diversity. Attending diverse middle schools and having more cross-race friends is associated with more positive attitudes toward outsider groups, less social vulnerability, greater social and academic competence, and better mental health ( Graham, 2018 ; Williams and Hamm, 2017 ). Adolescence is a period of transformation in social cognition ( Blakemore and Mills, 2014 ; Giedd, 2015 ), so in light of the findings from psychobehavioral and cultural neuroscience research on the benefits of diversity, important questions may be asked about whether adolescence is a critical period for providing exposure to difference. For instance, should we expect the benefits of exposure to diversity to be maximized if such exposure occurs during adolescence, or are benefits most likely with cumulative exposure that begins well before this period? 9

Identity Development in Context

Identity development takes place in specific socio-cultural, political, and historical contexts. As an example, consider recent cultural and political shifts regarding same-sex relationships in the United States: in the period of one generation there has been dramatic social change regarding understanding and awareness of LGBTQ lives and issues. For context, consider that less than 20 years ago, marriage between same-sex couples was just beginning to be recognized anywhere in the world (the first country to do so was the Netherlands in 2001); less than 20 years later, 25 countries have legalized same-sex marriage, and recent surveys show that most young people in the United States approve of same-sex marriages ( Pew Research Center, 2015 ). Moreover, the identity language and labels used among youth who are often placed under the umbrella of LGBTQ have continued to rapidly evolve. A growing number of LGBTQ youth say they have a nonbinary gender identity (i.e., neither male nor female) or sexual identity (e.g., pansexual, bisexual, queer) ( Hammack, 2018 ). Indeed, young people appear to be leading a movement toward challenging existing categories and constructing new identities.

Meanwhile, in the past decade there has been a dramatic change in public awareness and understanding of transgender identities. Popular attention to the gender changes of a number of celebrities coincided with growing emergence and awareness of transgender children. 10 Thus, a subject that was literally unknown by most people in the United States has within a decade become the subject of public discussion and political debate. School systems are grappling with gender change and accommodations for transgender students, and the typical developmental challenges of adolescence are being navigated by a growing number of openly transgender, gender-nonbinary, or gender-nonconforming adolescents ( Wilson et al, 2017 ).

Developmental scientists have recently called for a deeper investigation of the ways in which intersecting axes of oppression shape youth development, often referred to as “intersectionality” ( Crenshaw, 1990 ; Santos and Toomey, 2018 ; Velez and Spencer, 2018 ). Indeed, against a backdrop of social stratification and oppression, relationships between identity, experience, and behavior may not operate the same way for all youth ( Spencer, 1995 ). For example, the way in which knowledge is socially constructed contributes to maintaining systems and structures that control and exclude marginalized populations such as people with disabilities ( Peña et al., 2016 ). Smart and Smart (2007) argue that society has historically viewed people with disabilities from a medical perspective, in which individuals were labeled as ill, dysfunctional, and in need of medical treatment. This approach perpetuates an ableist worldview that suggests people with disabilities should strive toward an able-bodied norm, reflecting society's perceptions that certain abilities are essential to fully function in the world ( Hutcheon and Wolbring, 2012 ). This example highlights why an intersectional perspective is important for understanding adolescent psychosocial development in context, both for considering systemic factors that shape opportunities and for broadening the range of questions, values, samples, and experiences that have been defined and studied from a dominant-group perspective ( Syed et al., 2018 ). Ultimately, intersectional approaches and related integrative models are needed to understand how youth development in context can lead to further marginalization for some youth ( Causadias and Umaña-Taylor, 2018 ) or to adaptability and resilience for others ( Gaylord-Harden et al., 2018 ; Suárez-Orozco et al., 2018 ).

We have long considered identity exploration as a hallmark of adolescence. An adolescent's identity is an emerging reflection of his or her values, beliefs, and aspirations, and it can be constructed and reconstructed over time and experience. Multiple factors—family, culture, peers, media—shape identity development, but young people are also active agents in the process. Movement toward stability and coherence is normative, yet there remain dynamic elements that shape the relationship between identity and behavior; teens often select activities that feel identity-congruent, and may interpret and respond to a given situation based on aspects of identity that are salient in the moment ( Oyserman, 2015 ; Oyserman and Destin, 2010 ). This has implications for adolescents' experiences in important contexts such as school. Identity processes are connected to a larger set of self-development characteristics, including self-regulation, self-efficacy, and a sense of agency, all of which youth need to help develop and commit to meaningful goals. Ensuring that adolescents understand how all identities can be consistent with their current academic choices and future educational and vocational aspirations is an important consideration for the education system and is discussed further in Chapter 6 .

Recent neuroscientific findings suggest that changes in social and affective regions of the brain correspond to developmental changes in identity development. Moreover, identity and self-related processes may play a greater role in decision making during adolescence than they do in childhood. Youth may also experience identity congruence, affirmation, or marginalization through their interpersonal interactions with policies, sociopolitical events, and historical factors. Ultimately, how adolescents' multifaceted identities are manifested—neurobiologically, behaviorally, and otherwise—and the role identity plays in their overall well-being depend a great deal on experiences in context. This requires us to reflect on the nature of the contexts in which adolescents are developing their identities.

Consider, for example, that a youth's likelihood of involvement in extremist organizations may be heightened as they search for meaningful in-groups, if they accept group beliefs without questioning them (i.e., identity foreclosure), and/or if they feel their personal or group identities are under threat ( Dean, 2017 ; Schwartz et al., 2009 ). As Schwartz and colleagues note, “providing mainstream paths for young people, within the cultural constraints of their society, can help to alleviate the anger, frustration, and hopelessness leading many young people [towards extremism]” ( Schwartz et al., 2009 , p. 553). While the overwhelming majority of adolescents do not become involved in extremist groups, acknowledging this possibility underscores how the significant opportunities afforded by identity exploration in adolescence can be thwarted by conditions that increase the likelihood of marginalization.

Adolescent Capacity for Self-Direction

As adolescents ask, “Who am I?” their growing cognitive capacities also permit reflection on themselves in relation to a broader collective: “What is my role in my school? my community? my society?” As adolescents grow older, they have more opportunities to make their own choices in domains that matter for future outcomes, and their capacity to make such choices also increases; Box 2-1 describes youths' perspectives on this emerging autonomy, agency, and independence.

Youth Perspectives: Sense of Agency, Purpose, and Autonomy.

In the following section, we discuss developmental changes in autonomy, purpose, and agency in adolescence. One might think of these three things not only as competencies that develop within adolescents, but also as resources or opportunities they need to thrive as they transition into adult roles. Framing them as both capacities of the individual youth and as characteristics afforded by supportive settings reminds us that developmental pathways that lead to thriving in adulthood are not forged by adolescents alone, but instead require alignment between youths' strengths and the resources available in their environments.

Striving for Autonomy While Remaining Connected

For most adolescents, establishing a level of independence and self-sufficiency is normative. This typically involves individuating from one's family. However, gaining a sense of autonomy does not mean that adolescents strive to become detached from their family. Indeed, the developmental task for most teens is about establishing a balance between autonomy and connection ( McElhaney et al., 2009 ). While many adolescents would like more autonomy for making decisions, this varies by age and domain ( Daddis, 2011 ; Smetana, 2011 ). Most youth report having enough autonomy when it comes to making moral decisions, but younger adolescents tend to desire more autonomy for personal matters (e.g., hairstyle and clothing choices) and conventional matters (e.g., cursing/swearing) than older teens. This increase in desired autonomy among younger teens maps onto findings that older teens report having more autonomy across multiple domains than their younger peers.

Not only do young adolescents have less autonomy than older youth, they also tend to overestimate how much autonomy their peers have; in other words, younger adolescents tend to think their friends are allowed to have more control over their choices and behaviors than they actually do. Adolescents who think they have low levels of autonomy over decisions also tend to believe their friends have more autonomy, whereas adolescents who feel they have enough autonomy are less influenced by perceptions of their peers ( Daddis, 2011 ).

Autonomy and Culture

The concept of “autonomy” implies independence, which generally is accepted as a core value among cultures oriented toward individualism. In contrast, one might expect youth from cultures oriented toward collectivism and interdependence to be more inclined toward harmonious, less conflictual relationships with parents and a lower desire for individuation. However, evidence suggests that teens in many cultures, both those labeled “individualist” and those labeled “collectivist,” strive to develop autonomy, and levels of parent-teen conflict are similar in immigrant and nonimmigrant families ( Fuligni and Tsai, 2015 ; Tsai et al., 2012 ). Studies of youth from multiple ethnic backgrounds in the United States, including those who are U.S.-born and those from immigrant families, show that most adolescents express a desire to have control over personal choices ( Phinney et al., 2005 ). Importantly, while youth across cultural backgrounds identify autonomy as important, there can be culturally relevant variations in how autonomy is defined. For example, some adolescents from Asian American heritage groups describe autonomy through the lens of “interdependence” ( Russell et al., 2010 ).

Examining Autonomy and Culture “Under the Skin”

While all teens may desire autonomy from their parents and seek identities and self-definitions that go beyond their role in the family, adolescents in immigrant families in the United States may have a stronger sense of family obligation relative to youth in nonimmigrant families. Recent findings from the field of cultural neuroscience demonstrate the integration between biology and sociocultural context ( Telzer et al., 2010 ; Fuligni and Telzer, 2013 ). In one study, White and Latinx older adolescents participated in laboratory-based tasks in which they were asked to allot cash rewards to themselves or to their families; during the task their patterns of brain activity were observed using functional magnetic resonance imaging (fMRI). While youth from both groups allotted cash rewards to family at the same rate, among Latinx youth the “reward centers” of the brain were more activated when they contributed to family, whereas White youth showed more brain activity in the reward centers when allotting cash to themselves. Across both groups, those who felt a stronger sense of family identification and who felt fulfilled by contributing to family had more activation in the reward centers of the brain when allotting cash to their family. Thus, the cultural meaning that youth and families make around issues of autonomy, connection, and obligation are connected to neurobiological responses in the context of family contribution.

Some studies show linkages between broad cultural orientations, such as being more individually or more collectively oriented, and patterns of neural response ( Mrazek et al., 2015 ). Moreover, cultural neuroscientists posit that developmental growth and transitions in neural activity shape the transmission of cultural values, like preference for social hierarchy ( Mrazek et al., 2015 ). In addition to the vmPFC and the anterior cingulate cortex regions of the brain implicated in personal identity development, researchers speculate that the temporoparietal junction may be implicated in culturally embedded identities that orient youth toward independence or interdependence ( Cheon et al., 2011 ; Mrazek et al., 2015 ; Saxe et al., 2009 ).

Finding Meaning and Taking Action: Purpose and Agency

Purpose has been defined as “a stable and generalized intention to accomplish something that is at once meaningful to the self and of consequence to the world beyond the self” ( Damon et al., 2003 , p. 121) and also as “a central, self-organizing life aim that organizes and stimulates goals, manages behaviors, and provides a sense of meaning” ( McKnight and Kashdan, 2009 , p. 242). Thus, one's sense of purpose can be oriented toward life aims that are self-focused or toward aims that transcend the self ( Sumner et al., 2018 ; Yeager et al., 2012 ). Higher scores on measures of purpose are generally associated with more positive psychological wellbeing, a more consolidated identity, a deeper sense of meaning, and fewer health-compromising behaviors; a sense of purpose is also positively correlated with religiosity and spirituality ( Burrow and Hill, 2011 ; Sumner et al., 2018 ). Moreover, there is evidence that purpose helps explain associations between identity commitment and positive youth adjustment ( Burrow and Hill, 2011 ).

For all adolescents, developing a sense of purpose requires some support, particularly while their sense of orientation toward the future is still under development ( Steinberg et al., 2009 ). For adolescents who experience marginalization—by virtue of membership in one or more groups that experience systemic oppression ( García Coll et al., 1996 ; Causadias and Umaña-Taylor, 2018 )—developing a sense of purpose may be compromised if structural discrimination makes links between present action and future outcomes unpredictable (e.g., for adolescents with an undocumented immigration status) ( Gonzales, 2016 ; Sumner et al., 2018 ). Adolescents experiencing marginalization may internalize such messages as they become more aware of their own external realities; the messages may also be reinforced through family socialization practices. For example, researchers studying low-income White adolescents suggest that parents' messages of “isolation and threat, helplessness and hopelessness, and live fast, die young,” which may be adaptive in the short-term and in the immediate settings where the families live, can compromise youth's sense of purpose, hope, and agency ( Jones et al., 2018 ).

Agency to Take Action

Adolescents' growing competencies in flexible problem-solving, their awareness of and concern with others, and their openness to exploration and novelty ( Crone and Dahl, 2012 ) make adolescence a particularly opportune time to allow for agency and leadership ( Flanagan and Christens, 2011 ). Indeed, young people have been at the helm of social movements for centuries. For some youth, active civic engagement may be an adaptive means for coping with systemic injustice, particularly for those in historically marginalized communities ( Diemer and Rapa, 2016 ; Ginwright et al., 2006 ; Hope and Spencer, 2017 ). In a recent multi-methods study of middle and late adolescents in seven community organizations (four in the United States, two in Ireland, and one in South Africa), many of which served low-income or working class communities, researchers documented multiple benefits of civic engagement. Findings suggest the context of youth organizing promoted the skills of critical thinking and analysis, social and emotional learning, and involvement in community leadership and action ( Watts, 2018 ; Watts et al., 2011 ).

In relation to research on community leadership and action, recent work has examined the construct of “critical consciousness” among adolescents ( Watts et al., 2011 ). Contemporary definitions of critical consciousness, grounded in the work of Brazilian educator Paolo Freire (1970) , include the elements of critical reflection, motivation, and action ( Diemer et al., 2015 ). These core concepts have informed the development of new measures of critical consciousness for middle and late adolescents (e.g., Diemer et al., 2017 ; McWhirter and McWhirter, 2016 ; Thomas et al., 2014 ). Youth with higher levels of critical consciousness are more likely to recognize injustice and may feel a greater sense of agency or efficacy in responding to it ( Diemer and Rapa, 2016 ; Shedd, 2015 ). Critical consciousness is also positively associated with vocational and educational attainment ( Diemer et al., 2010 ; Luginbuhl et al., 2016 ; McWhirter and McWhirter, 2016 ).

Capacity for Self-Direction as a Developmental Opportunity

While there is general agreement about the benefits of purpose and agency in adolescence, ongoing work is needed to better understand the circumstances under which they are best fostered and the way they relate to other processes (e.g., critical consciousness) and to behavior (e.g., volunteering, social activism). For instance, do opportunities for critical reflection contribute to an adolescent's sense of purpose? Are community service or civic action necessary for building an adolescents' belief in their own agency to create change?

Additional research might determine whether a sense of purpose that transcends the self has greater positive impact on an adolescent than one that is more self-focused. Current work in this area suggests that a self-transcendent sense of purpose better predicts academic regulation, performance, and persistence among high school students ( Yeager et al., 2014 ); however, whether this extends beyond the school context is unclear. As research methods and methods in studies of critical consciousness continue to advance (e.g., Diemer et al., 2015 ), we may have a better understanding of how this particular kind of agency develops across adolescence, and for whom and under what conditions greater critical consciousness is most beneficial. Finally, an emerging body of work on adolescents' contribution mindset (i.e., giving to others; Fuligni and Telzer, 2013 ) and value-based decision making ( Pfeifer and Berkman, 2018 ) may provide some insight into the neurobiological correlates underlying the cognitive and social skills needed for developing purpose.

Over the course of adolescence, youth gain the cognitive skills needed to reflect on complex questions about their aims in life and their role in the world. They can question the legitimacy and fairness of everyday experiences and of social institutions. Indeed, the social systems they must navigate—schools, employment, health care, justice—are quite complex and often require them to engage in independent decision making. Two important questions stemming from this reality are, “What experiences are needed to support adolescents' agency as they transition into adult roles?” and “What might our society look like if all adolescents felt a sense of commitment to something personally meaningful and goal-directed that extends beyond the self?” ( Bronk, 2014 ).

Supporting opportunities for autonomy and agency and fostering a sense of purpose may help adolescents explore meaningful questions about who they are, and about their place in the world and their capacity to shape it. Continuing shifts in the social, cultural, economic, and technological contexts in which today's adolescents are developing require thoughtful consideration as to how, when, and where adolescents can find and act upon ideas and issues they find meaningful. For example, religion has traditionally been a context where youth have found purpose and meaning, and religious involvement is associated with civic engagement ( Furrow et al., 2004 ; Pew Research Center, 2019 ; Sumner et al., 2018 ). Religion can also be protective against stressors like discrimination and against negative mental health outcomes ( Hope et al., 2017 ). However, adolescents and young adults today are less likely to be religiously engaged than those in earlier generations ( Pew Research Center, 2018 ). If faith-based institutions are playing a less central role in the lives of greater numbers of today's adolescents, this brings to the fore questions about the alternative settings and experiences to which youth are turning and whether these settings play a comparable role in fostering involvement and purpose.

Although there is great variation in how the skills of autonomy, purpose, and agency manifest and how they are defined and valued, adolescents should be afforded opportunities—in families, schools, or out-of-school settings—to develop them. Such skills not only are important to support the transition to adulthood, but also make adolescence itself a period that fosters a propensity to choose their own paths in life and to shape the roles they want to play in their communities ( Fuligni, 2018 ).

Adolescence, spanning the period from the onset of puberty to adulthood, is a formative period where changes in cognition, affect, and interpersonal behavior occur alongside the most extensive biological transitions since infancy, especially with respect to pubertal and brain development. Collectively, the pubertal, neurobiological, cognitive, and psychosocial changes occurring during adolescence mark this as a period of great opportunity for adolescents to flourish and thrive.

While often thought of as a time of turmoil and risk for young people, adolescence is more accurately viewed as a developmental period rich with opportunity for youth to learn and grow. If provided with the proper supports and protection, normal processes of growth and maturation can lead youth to form healthy relationships with their peers and families, develop a sense of identity and self, and experience enriching and memorable engagements with the world. Adolescence thus forms a critical bridge between childhood and adulthood and is a critical window of opportunity for positive, life-altering development. As a positive window of opportunity, adolescence marks a period of optimism, where the assets of youth and their development may be capitalized for the betterment of society.

Important questions emerge from these findings. What are the “windows of opportunity” for promoting a positive developmental trajectory and adaptive plasticity? What are the mechanisms that shape developmental trajectories, for better or worse, during adolescence and over the life course? To begin to answer these, in the next chapter we consider the emerging science of epigenetics as it reveals the ongoing plasticity of the brain and the reciprocal influences of brain on body and vice versa.

The average child in the United States experiences the onset of puberty between the age of 8 and 10 years.

HPG hormones can bind within cell nuclei and change the transcription and expression of genes to regulate further hormone production, brain function, and behavior ( Melmed et al., 2012 ; Sisk and Foster, 2004 ). The process begins in the brain when a gonadotropin-releasing hormone (GnRH) is secreted from the hypothalamus. The activation of GnRH is not unique to the pubertal transition; GnRH is also active during pre- and perinatal periods of development but undergoes a quiescent period during the first year of postnatal life until it reawakens during the pubertal transition. GnRH stimulates the pituitary gland to secrete luteinizing hormone (LH) and follicle-stimulating hormones (FSH), which then stimulate the ovary and testes to secrete estradiol and testosterone.

For more information on the National Longitudinal Study of Adolescent Health, see https://www .cpc.unc.edu /projects/addhealth .

See Chapter 3 for a discussion of the adaptive plasticity of adolescence and the potential of interventions during adolescence to mediate deficiencies from earlier life periods.

“Connectivity” refers to the formation of synapses, or connections between neurons; groups of interconnected neurons form circuit-like neural networks.

The threat cues used in the research cited here were pictures of “fearful faces,” which serve as a social cue of impending danger.

Impulsive action in response to potential threat was assessed using a “go/no-go” task. Simply put, this is a task in which participants are presented with two types out of three facial emotions (“happy” or “calm” or “fearful”) that are randomly assigned as “go” (stimulate action = press a button) or “no-go” (inhibit action = do not press button).

While there may be asynchronous development of circuits within specific regions of the brain during adolescence, this does not mean that these regions are “fixed” by the end of adolescence; instead, people retain the ability for neural plasticity and change throughout the life course (see Chapter 3 ).

For instance, rodent models suggest that empathy is shaped by social context (e.g., rats usually assist members of their own genetic strain, but will extend their prosocial behavior to unrelated peers if they are raised together; Bartal et al., 2011 ; Meyza et al., 2017 ).

See, for example, “Beyond ‘He' or ‘She': The Changing Meaning of Gender and Sexuality,” TIME Magazine, March 16, 2017.

Cite this Page National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Division of Behavioral and Social Sciences and Education; Board on Children, Youth, and Families; Committee on the Neurobiological and Socio-behavioral Science of Adolescent Development and Its Applications; Backes EP, Bonnie RJ, editors. The Promise of Adolescence: Realizing Opportunity for All Youth. Washington (DC): National Academies Press (US); 2019 May 16. 2, Adolescent Development.
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Middle Childhood (6-8 years of age)

Developmental Milestones

Middle childhood brings many changes in a child’s life. By this time, children can dress themselves, catch a ball more easily using only their hands, and tie their shoes. Having independence from family becomes more important now. Events such as starting school bring children this age into regular contact with the larger world. Friendships become more and more important. Physical, social, and mental skills develop quickly at this time. This is a critical time for children to develop confidence in all areas of life, such as through friends, schoolwork, and sports.

Here is some information on how children develop during middle childhood:

Emotional/Social Changes

Children in this age group might:

Show more independence from parents and family.
Start to think about the future.
Understand more about his or her place in the world.
Pay more attention to friendships and teamwork.
Want to be liked and accepted by friends.

Thinking and Learning

Show rapid development of mental skills.
Learn better ways to describe experiences and talk about thoughts and feelings.
Have less focus on one’s self and more concern for others.

Positive Parenting Tips

Following are some things you, as a parent, can do to help your child during this time:

Show affection for your child. Recognize her accomplishments.
Help your child develop a sense of responsibility—ask him to help with household tasks, such as setting the table.
Talk with your child about school, friends, and things she looks forward to in the future.
Talk with your child about respecting others. Encourage him to help people in need.
Help your child set her own achievable goals—she’ll learn to take pride in herself and rely less on approval or reward from others.
Help your child learn patience by letting others go first or by finishing a task before going out to play. Encourage him to think about possible consequences before acting.
Make clear rules and stick to them, such as how long your child can watch TV or when she has to go to bed. Be clear about what behavior is okay and what is not okay.
Do fun things together as a family, such as playing games, reading, and going to events in your community.
Get involved with your child’s school. Meet the teachers and staff and get to understand their learning goals and how you and the school can work together to help your child do well.
Continue reading to your child. As your child learns to read, take turns reading to each other.
Use discipline to guide and protect your child, rather than punishment to make him feel bad about himself. Follow up any discussion about what not to do with a discussion of what to do instead.
Praise your child for good behavior. It’s best to focus praise more on what your child does (“you worked hard to figure this out”) than on traits she can’t change (“you are smart”).
Support your child in taking on new challenges. Encourage her to solve problems, such as a disagreement with another child, on her own.
Encourage your child to join school and community groups, such as a team sports, or to take advantage of volunteer opportunities.

Child Safety First

More physical ability and more independence can put children at risk for injuries from falls and other accidents. Motor vehicle crashes are the most common cause of death from unintentional injury among children this age.

Protect your child properly in the car. For detailed information, visit the American Academy of Pediatrics’ Car Seats: Information for Families external icon .
Teach your child to watch out for traffic and how to be safe when walking to school, riding a bike, and playing outside.
Make sure your child understands water safety, and always supervise her when she’s swimming or playing near water.
Supervise your child when he’s engaged in risky activities, such as climbing.
Talk with your child about how to ask for help when she needs it.
Keep potentially harmful household products, tools, equipment, and firearms out of your child’s reach.

Healthy Bodies

Parents can help make schools healthier. Work with your child’s school to limit access to foods and drinks with added sugar, solid fat, and salt that can be purchased outside the school lunch program.
Make sure your child has 1 hour or more of physical activity each day.
Keep television sets out of your child’s bedroom. Set limits for screen time for your child at home, school, or afterschool care and develop a media use plan for your family. external icon
Practice healthy eating habits and physical activity early. Encourage active play, and be a role model by eating healthy at family mealtimes and having an active lifestyle.
Make sure your child gets the recommended amount of sleep each night: For school-age children 6-12 years, 9–12 hours per 24 hours (including naps)

For More Information

Infants and toddlers
Middle childhood
Adolescence

CDC’s “Learn the Signs. Act Early.” Campaign For more details on developmental milestones, warning signs of possible developmental delays, and information on how to help your child’s development, visit the “Learn the Signs. Act Early.” campaign website.

CDC’s Parent Information (Children 0―3 years) This site has information to help you learn how to give your child a healthy start in life.

CDC’s Essentials for Parenting Toddlers and Preschoolers Learn ways you can help build a safe, stable, and nurturing relationship with your child.

CDC’s Breastfeeding Information This site has answers to frequently asked questions about breastfeeding.

CDC’s Information on Infant and Toddler Nutrition Tips for Parents – Ideas to help children maintain a healthy weight.

CDC’s Protect the Ones You Love CDC’s Injury Center has information on how you can protect your child from drowning and other common causes of injury.

CDC’s Information on Vaccinations View the immunization schedule for infants and children and find out if your child’s vaccinations are up to date.

My Plate – Infants external icon The U.S. Department of Agriculture provides information on health and nutrition for 2 through 5 years of age.

My Plate – Toddlers external icon The U.S. Department of Agriculture provides information on health and nutrition for toddlers

HealthyChildren.org external icon AAP’s Healthy Children website provides information on feeding, nutrition, and fitness for all developmental stages from infancy to young adulthood.

Just in Time Parenting external icon (JITP) Quality, research-based information to families at the time it can be most useful.

Healthy Kids Healthy Future external icon You will find information on physical activity for young children and on ways to keep them moving.

National Highway Traffic Safety Administration external icon (NHTSA) NHTSA has information on safety recalls and safety tips for children riding in motor vehicles, walking, biking, playing outside, waiting at school bus stops, and more.

National Institute of Child Health and Human Development. external icon (NICHD) Visit NICHD to learn how to reduce the risk of Sudden Infant Death Syndrome (SIDS) and about safe sleep environments.

World Health Organization information on infant nutrition external icon This site has information to promote proper feeding for infants and young children.

CDC’s Parent Information (Children 4−11 years) This site has information to help you guide your child in leading a healthier life.

CDC’s Healthy Weight Information . Tips for parents – Ideas to help children maintain a healthy weight.

CDC’s Youth Physical Activity Guidelines This site has information on how to help children be active and play.

My Plate- Preschoolers external icon The U.S. Department of Agriculture provides information on health and nutrition for preschoolers.

CDC’s Parent Information (Children 4 — 11 years) This site has information to help you guide your child in leading a healthier life.

CDC’s Youth Physical Activity Basics This site has information on how to help children be active and play.

CDC’s Kids Quest Kids Quest is a CDC website designed for students in fourth, fifth, and sixth grades, to get them to think about people with disabilities and some of the issues related to daily activities, health, and accessibility.

CDC’s BAM! Body and Mind CDC’s BAM! Body and Mind is a website designed for kids 9 through 13 years of age to give them the information they need to make healthy lifestyle choices. The site focuses on topics that kids told us are important to them—such as stress and physical fitness—using kid-friendly lingo, games, quizzes, and other interactive features.

My Plate – Kids external icon . The U.S. Department of Agriculture provides information on health and nutrition for children over 5 years of age.

HealthyChildren.org external icon AAP’s Healthy Children website provides information on feeding, nutrition, and fitness for all developmental stages from infancy to young adulthood. Visit this website to learn more about emotional problems external icon , learning disabilities external icon and other health and development concerns.

Let’s Move-Kids external icon Five simple steps for parents towards creating a healthy environment at home.

StopBullying.gov external icon StopBullying.gov provides information from various government agencies on how children, parents, educators and others in the community can prevent or stop bullying.

SAMHSA’s KnowBullying app external icon A free app for parents to help prevent bullying, created by the Substance Abuse and Mental Health Agency (SAMHSA).

Teens Health external icon Visit this site for information on healthy eating and exercise external icon for children and teenagers, safety tips for your child at home external icon when you can’t be there, and other important health and safety topics.

CDC’s Adolescent and School Mental Health Learn how connection is key to good adolescent mental health.

CDC’s Parent Information (Teens 12— 19) This site has information to help you learn how to guide your teen to be safe and become a healthy and productive adult.

CDC’s Pregnancy Prevention for Teens . Tips and information especially for teens and designed with input from teens.

CDC’s BAM! Body and Mind CDC’s BAM! Body and Mind is a website designed for kids 9 through 13 years of age, to give them the information they need to make healthy lifestyle choices. The site focuses on topics that kids told us are important to them—such as stress and physical fitness—using kid-friendly lingo, games, quizzes, and other interactive features.

CDC’s Information on Lesbian, Gay, Bisexual, and Transgender Youth Health Learn about the physical and mental health of lesbian, gay, bisexual, and transgender youth

American Academy of Child & Adolescent Psychiatry external icon The American Academy of Child & Adolescent Psychiatry has many fact sheets for parents on child and adolescent health and development.

My Plate – Teen external icon The U.S. Department of Agriculture provides information on health and nutrition for teens.

National Institute of Mental Health external icon The National Institute of Mental Health has information on mental disorders affecting children and adolescents, including anxiety and depression.

StopBullying.gov external icon StopBullying.gov provides information from various government agencies on how children, parents, educators, and others in the community can prevent or stop bullying.

Substance Abuse and Mental Health Services Administration (SAMHSA) external icon SAMHSA works to improve the quality and availability of substance abuse prevention, alcohol and drug addiction treatment, and mental health services.

Teens Health external icon Visit this site for information on healthy eating and exercise for children and teenagers.

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The Denver II Test of Developmental Milestones Essay

Introduction, interpreting/responding.

Nurses and medical practitioners working with special needs children have responsibilities requiring unwearied attention and dedication. However, adhering to practice standards and applying relevant theoretical concepts in assisting these students promises the best results as practitioners are better positioned to provide appropriate guidance. I had an opportunity to work with special needs educators, nurses, and students at the Little Light House School in Tulsa, where I completed my clinical. The institution is dedicated to improving the lives of children with disabilities by training them, providing personalized care, and enhancing their development in different areas. Although I observed several students from three and a half to five years and helped my friends complete their projects, a four-year-old girl with autism caught my attention as she was charismatic and ambitious. The following report details the information obtained from the Denver II test performed on this girl, a reflection of critical lessons, and an article review to further expound on the condition’s attributes.

Mary, not her real name, is a four-year-old girl enrolled at the Little House School Tulsa due to her coping and learning disabilities. Mary is different from other students because her limitations are not easily noticeable. However, keenly observing her actions reveals that she has autism as she experiences difficulties in expressing herself, maintaining long conversations, and playing with others. Mary’s age is adjusted for prematurity to three years as she exhibits appropriate developmental milestones and can perform tasks as well as others in her age bracket but struggles with most initiatives. Autism Spectrum Disorder is a condition that interferes with an individual’s behavioral, social, and communication abilities (Lord et al., 2018). Nevertheless, children diagnosed with autism have unique issues and different strengths and weaknesses. Although Mary is charismatic and intelligent, she finds it hard to engage with others and concentrate on her work for extended periods. Additionally, she has problems imitating actions, and her parents suggest that she does not react well to situational or environmental changes.

The Denver Developmental Screening Test (Denver II) is a widely adopted instrument to evaluate child development and determine whether they appropriately reach their milestones. The results obtained from this test provide information about a child’s abilities and weaknesses and can guide decision-making on solutions to support their positive development (Rouvier et al., 2022). Denver II notes a child’s attributes based on four categories listed on the sheet, including social contact, fine motor skills, language, and gross motor skills. Thus, the test is reliable in determining issues educators should address when dealing with particular students.

The initial test involved observing Mary’s social development and abilities. The activities tested at Mary’s adjusted age include brushing her teeth with no assistance, playing board or card games, dressing, and putting on a T-shirt. The instrument evaluates preparing cereals at four years, and all skills are assessed at three years. Like three and four-year-old children, Mary cannot brush her teeth without help or play board and card games. Additionally, she cannot wholly dress but can put on a T-shirt. At her age, the Denver II test suggests that Mary should be able to dress. Thus, this is the only activity in this group where the child experiences limitations.

The fine motor and adaptive skills the child should exhibit at Mary’s adjusted age include picking a longer line, copying a circle, wiggling the thumb, building a tower using ice cubes, and imitating a vertical line. At four years, activities include drawing a person – 3 and 6 parts – and copying plus and square shapes. The child appropriately completed the tests by easily imitating a long line and building a tower of eight cubes. However, she experienced several issues copying all shapes, and it took some time for her to deliver as expected.

The Denver II test also indicates a child’s language development by assessing the ability to follow instructions. At her adjusted age, Mary should know three adjectives, name four colors, understand four prepositions, exhibit intelligible speech, know four actions, use three objects, count one block, one color, and use two objects. At four years, she should define seven words and two opposites, know five words, name four colors, and understand four prepositions. Unlike most children her age, Mary could not recollect and provide accurate responses when naming colors and explaining adjectives. However, she could perform other actions like students at her age.

The skills evaluated at Mary’s adjusted age for gross motor development include balancing each foot for 2 and 1 seconds, broad jumping, and throwing a ball overhand. At four years, the child should balance each foot for 4, 3, and 2 seconds and hop. According to the assessment, Mary could broad jump, throw a ball overhand, and balance each foot for 1 and 2 seconds. However, she could not balance her foot for four seconds, which is typical for four-year students. Thus, this section of the test reveals that Mary had surpassed the expected levels of gross motor development.

The general classroom objectives for the day involved assisting educators and students in carrying out initiatives and operating comfortably. The administration expected all volunteers to lend a hand, follow instructions and guidelines, assist students by not completing tasks for them, interact, play with them, and encourage them to perform to their best. These initiatives were implemented in the four developmental stages as the teachers provided a curriculum and specific task initiatives to facilitate language, fine motor, social, and gross motor skills. Children with autism experience developmental challenges with high-level skills (Lord et al., 2018). As a result, Mary’s therapy objectives included respecting her boundaries and space, assisting her in controlling behaviors such as rocking and hand flapping, and training her on how to express emotions. In addition, her management plan involves instructing her on how to convey her frustration in productive ways and encouraging her to make and maintain eye contact when communicating with others. These initiatives aimed at assisting her in coping with her environment and managing issues due to her disabilities.

The disciplinary measures adopted at the Little Light House School included a system of rewards and punishment, clearly defined expectations, simple language, establishing a routine, and praising students for reaching milestones. However, encouragement was practical as it allowed students to focus on their weaknesses and continuous advancement. The teaching adaptations for special needs children like Mary include embracing differences, advocating, being patient, keeping instructions simple, creating improvement opportunities, fostering a supportive environment, and observing high organization levels. The role of the nurse practitioner at Little Light House was to assist students with tube feeding and wound care. However, nurses in special needs institutions are also responsible for outlining a plan of care, evaluating health needs, and providing appropriate accommodation. Thus, the nurses on duty attended to all their responsibilities as required.

My clinical project at the Little Light House School exposed me to unmatched experiences as I enjoyed spending time with the children and striking valuable bonds with the institution’s teachers and other volunteers. The most critical lesson I learned from the program was the essence of being prepared and the need for resilience. For example, dealing with special needs children and overseeing developmental improvement takes time and patience. Thus it is necessary to embark on recommended solutions without giving up. Additionally, service providers should be prepared to tackle complex challenges because they work in high-pressure environments. A child I was working with fell, hit his head and sustained an injury. However, the nurse on duty quickly attended to him and calmed him down. Sitting down and dealing with students at a personalized level while addressing all their needs are some new concepts I learned. In addition, the program reinforced the importance of teamwork and collaboration in delivering on tasks. Hence, it is best to always be prepared to counter critical issues as they can arise at any time.

Technological solutions effectively address issues that limit autistic students from performing and living normally. The article by Wood-Downie et al. (2021) investigated the implication of digital stories in transition planning and assessment of children with autism. The researchers suggest that preschool children with autism experience hurdles transitioning from one activity to another. However, digital stories that target particular developmental skills can enable educators to prepare these children for changes and facilitate better outcomes (Wood-Downie et al., 2021). The article supports the growth and development of autistic children by providing a solution to allow them to accommodate change and new situations. Thus, parents can learn to use digital stories to train their children on initiatives depending on their ages and milestones.

Children living with disabilities experience significant challenges because of negligence and insufficient resources to cater to their issues. However, institutions such as the Little Light House School have made obtaining high-quality care services easier and created opportunities for these children. During my clinical, I interacted with special needs children and assisted teachers and other volunteers in the facility to deliver on their objectives. Nevertheless, I performed a Denver II test on a female student with autism. The results revealed that the child had unique abilities but could not deliver on basic activities. Additionally, she lacks appropriate language and social skills, thus interfering with her ability to socialize with others. Regardless, the institution is staffed with professional nurses, educators, and volunteers who assist the students and oversee initiatives.

Lord, C., Elsabbagh, M., Baird, G., & Veenstra-Vanderweele, J. (2018). Autism spectrum Disorder . The Lancet , 392 (10146), 508-520. Web.

Rouvier, M. E., Granana, N., Ruiz, F. R., Zeltman, A., & Gil, S. R. (2022). Screening for Autism

Spectrum disorders in underserved populations: Global versus specific surveillance instruments . Advances in Neurology and Neuroscience. 5 (3) , 155 , 160 , 2. Web.

Wood-Downie, H., Ward, V. C. S., Ivil, K., Kovshoff, H., & Parsons, S. (2021). Using Digital Stories for assessments and transition planning for autistic preschool children . Educational and Child Psychology , 38 (3), 62-74. Web.

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