Child development and milestones

Last updated: October 26, 2023

Summarytoggle arrow icon

Early childhood, which typically spans from birth to 8 years of age, is characterized by rapid growth and development. Close monitoring during this period ensures children are meeting age-specific milestones and that deviations from expected developmental trajectories are quickly identified. Developmental delays affect ∼ 15% of children and can impact more than one domain (i.e., physical, language, cognitive, and social and emotional development); early identification and treatment can improve outcomes. Developmental milestones are an important component used to track a child's progress over time and provide a framework by establishing a set of skills or behaviors that most children are expected to achieve by a certain age. A child's development should be assessed at every well-child visit and whenever there is a concern for abnormal development. For children who are not meeting their milestones, an evaluation of abnormal pediatric development and relevant referrals are indicated.

See “Well-child visits” for more information on routine health assessments. For information on growth below the expected parameters for age, see “Growth faltering.”

Overview of normal developmenttoggle arrow icon

Normal development in childhood involves the evolution and resolution of primitive reflexes, and the sequential development of motor, language, cognitive and social skills (tracked using developmental milestones). Throughout childhood, various behaviors (e.g., stranger anxiety, magical thinking, imaginary companions) may also be temporarily observed and are part of normal development; caregivers should be reassured that these behaviors will resolve as children age.

Primitive reflexestoggle arrow icon

General principles [1]

  • Primitive reflexes are transient reflexes that manifest during infancy and disappear when subcortical motor inhibitory pathways develop (usually within the 1st year of life).
  • Evaluation of primitive reflexes is an essential part of the newborn examination.
  • Abnormal primitive reflexes are those that are absent, asymmetric, and/or persist past the expected age range.

Multiple primitive reflexes in adults (i.e., frontal release signs) indicate frontal lobe dysfunction. [3][4]

Overview of primitive reflexes

Overview of primitive reflexes [5][6]
Reflex Description Typical age range [5] Clinical significance
Glabellar tap sign [4]
  • Tapping the glabella elicits blinking.
  • Clinical significance unknown
Snout reflex [4]
  • Applying light pressure to closed lips causes the lips to pucker.
Rooting reflex
  • Stroking the cheek causes the mouth to open and the head to turn towards the stimulus.
Sucking reflex
  • Touching the lips and/or oral palate elicits sucking of the stimulus.
  • Early in utero –3 months [5]
Asymmetrical tonic neck reflex (ATNR)
  • Birth7 months [5][6]
Moro reflex (Startle reflex)
  • When the infant experiences a loud noise or sudden movement, they abduct and extend their arms and fingers before bringing them back to midline.
Palmar grasp reflex
  • Pressing or placing something into the infant's palm causes the fingers to flex towards the palm.
Plantar grasp reflex
  • Pressing the infant's sole beneath the toes causes their toes to flex towards the sole.
  • No clinical significance; evolutionary remnant [10]

Extensor plantar reflex (Babinski reflex)

  • Stroking the sole of the foot upwards elicits dorsiflexion of the big toe and fanning of the other toes.
  • Birth12 months (may be a normal finding up to 24 months) [5][11][12]
Landau reflex
  • When the infant is held prone in the air, the head raises, the back arches, and the legs extend.
  • When the head is flexed downwards, the legs will also flex downwards.
  • 3–24 months [5]
  • Aids in core strength and is required to roll from supine to prone [13]
  • Infants with hypotonia will have a weak Landau reflex (e.g., hang in an inverted U-shape), while those with hypertonia will remain stiff and resist head flexion. [11]
Parachute reflex
  • When the infant is held prone in the air, lowering the infant towards a flat surface causes the arms and the hands to reach towards the surface.
  • 7 months–throughout life [5]
  • Protective reflex when falling [6]
  • Absence may suggest neuromotor deficit [6]
Truncal incurvation reflex (Galant reflex) [14]
  • When the infant is held prone in the air, stroking the paravertebral region causes the lower back and hip to curve inwards on the same side.
  • Birth4 months [14][15]
  • Clinical significance unknown
Stepping reflex [16]
  • Holding the infant upright in a standing position elicits a walking motion, with alternating flexion and extension of the legs.

Developmental milestonestoggle arrow icon

General principles [17]

Developmental domains [5]

  • Motor development
    • Gross motor development: the development of movements (e.g., sitting up, walking) that require the use of large muscle groups
    • Fine motor development: the development of precise movements using hands and smaller muscles (e.g., picking up a small object)
  • Language development: the development of communication through either spoken or signed language
    • Receptive language: the ability to understand and process language
    • Expressive language: the ability to formulate language
  • Cognitive development: the development of reasoning and problem-solving skills
  • Social and emotional development: the development of self-regulation and attachment and interaction with others

Age-specific developmental milestones

A wait-and-see approach is no longer recommended for potential developmental delay. [20][22]

Developmental milestones in infants [20][21]

Overview of developmental milestones in infants [20][21]
Motor development Speech development Cognitive and social development
2 months
  • Gross motor
    • When prone, raises head up
    • Moves all extremities equally
  • Fine motor: hands are not always fisted
  • In addition to crying, makes other sounds
  • Reacts to startling noises
  • Social smile
  • Calms down when held or spoken to
  • Focuses on a face or toy
  • Recognizes caregivers
  • Eyes track caregiver (without crossing midline)

4 months

  • Gross motor
    • Good head control (may still bob)
    • When prone, uses forearms to prop self up
    • Brings hands to midline
    • Swats at toys
  • Fine motor: holds a toy when placed in the palm
  • Coos (i.e., makes vowel sounds)
  • Vocalizes when being spoken to
  • Orients to sound
  • Attempts to gain the attention of others
  • Chuckles
  • Interested in hands
  • When breast or bottle is visible, opens mouth to express hunger
6 months
  • Gross motor
    • Rolls from front to back [5][20]
    • When prone, uses hands to prop self up with straight arms
    • Sits in tripod position [20]
  • Back and forth vocalizing
  • Squeals
  • Blows raspberries
  • Laughs
  • Recognizes familiar individuals
  • Enjoys looking in the mirror
  • Reaches for desired objects
  • Shows disinterest in food if not hungry
  • Explores objects with mouth
9 months
  • Gross motor: independently gets into a steady seated position
  • Fine motor
    • Transfers objects from one hand to the other (voluntary palmar grasp)
    • Raking grasp
  • Repetitive babbling: repeats consonant sounds
  • Raises arms express desire to be picked up
12 months
  • Gross motor
    • Pulls self to a stand
    • Cruises
    • Drinks from an open cup with assistance
  • Fine motor: pincer grasp [20]
  • Waves good-bye
  • Pauses or stops when told “no”
  • Specifies mama/dada
  • Engages in interactive games
  • Places an object in a container
  • Looks for objects after they are hidden

Children, including twin siblings, develop at different speeds and one child's milestones should not be used to evaluate another child's development.

Developmental milestones in childhood [20][21]

Overview of developmental milestones in children 1–5 years [20][21]
Age Motor development Speech development Cognitive and social development
15 months
  • Gross motor: takes a few independent steps
  • Fine motor: brings food to mouth with fingers/hands
  • Protoimperative pointing
  • Says one specific word in addition to “mama/dada”
  • Follows one-step verbal commands with prompting
  • Glances at a familiar object when mentioned
  • Shares interests with others
  • Imitates actions
  • Attempts to use objects correctly
  • Claps to express excitement
  • Demonstrates affection
  • Stack two objects
18 months
  • Gross motor
    • Walks unassisted
    • Climbs on furniture independently
  • Fine motor
    • Scribbles
    • Drinks from an open cup independently
    • Independently feeds self with fingers/hands (no utensils)
    • Attempts feeding with spoon
  • Three specific words in addition to mama/dada
  • Follows one-step verbal commands without prompting
  • Protodeclarative pointing (indicates joint attention)
  • Tentatively moves away from caregiver
  • Assists with self-care routines
  • Looks at a book for short periods of time
  • Imitates household chores
  • Plays correctly with simple toys
2 years
  • Gross motor
    • Runs
    • Independently goes up the stairs with both feet on each step
    • Kicks ball independently
  • Fine motor: feeds self with spoon
  • Points to named objects
  • Combines two words together
  • Half of speech (∼ 50%) is understood by strangers [23]
  • In addition to waving and pointing, uses gestures to communicate
  • Shares in the emotions of others
  • In new situations, looks at the caregiver's face to guide reactions
  • Uses both hands to manipulate an object
  • Attempts to use complex toys
  • Plays with more than one toy at a time
2.5 years (30 months)
  • Gross motor: jumps with 2 feet off the ground
  • Fine motor
    • Removes some clothing
    • Twists wrist to open things
    • Turns single pages of a book
  • Says 50 words
  • Makes a 2-word sentence (noun + verb)
  • Names objects when pointed to
  • Uses personal pronouns [20]
  • Parallel play
  • Picks up toys after playing
  • Requests a caregiver watch them do something
  • Follows simple routines
  • Early pretend play with objects
  • Problem solves to obtain desired objects
  • Follows 2-step commands
  • Points to one color correctly
3 years
  • Gross motor: Can independently put on some clothes
  • Fine motor
    • Can string large items
    • Uses a fork
  • When asked, can say their first name
  • Uses question words
  • Correctly names actions in a picture
  • Converses back and forth at least two times
  • Most of speech (∼ 75%) is understood by strangers [23]
  • Resolving separation anxiety
  • Engages in cooperative play with other children
  • Copies a circle when demonstrated
  • Avoids dangers when warned
4 years
  • Gross motor: catches a big ball
  • Fine motor
    • Can undo buttons
    • Tripod pencil grasp
  • Makes 4-word sentences
  • Describes at least one event from the day
  • Can repeat some words from a story or rhyme
  • Correctly states the purpose of objects
  • Asks to play with children even if not present
  • Likes being assigned a role or task
  • Appropriately comforts others
  • Moderates behavior in different settings
  • Avoids dangers without a warning
  • Imaginative pretend play (e.g., dress-up)
  • Names a few colors
  • Repeats parts of a well-known story
  • Draws a person with three body parts
5 years
  • Gross motor: hops on a single foot
  • Fine motor: fastens buttons
  • Tells stories
  • Answers simple questions about a short story
  • Converses back and forth at least three times
  • Rhymes simple words
  • All of speech (∼ 100%) is understood by strangers [23]
  • Understands rules and taking turns
  • Performs for caregivers
  • Can perform simple chores
  • Can count to 10
  • Names some letters and numbers (e.g., 1–5)
  • Writes some letters from their name
  • Developing a concept of time
  • Attention span of 5–10 minutes (excluding screen time)

Common developmental behaviorstoggle arrow icon

Certain temporary pediatric behaviors are considered normal parts of cognitive, imaginative, and creative development, e.g.:

  • Stranger anxiety: when an infant is fearful of unknown individuals
    • Expected ages: 6 months–3 years [24]
    • Clinical features: crying and/or clinging to a known caregiver when around strangers
  • Separation anxiety: when an infant or young child is afraid of being separated from their caregiver
    • Expected ages: peaks between 9 and 18 months and resolves by 3 years of age [25]
    • Clinical features
      • Crying and/or clinging to a caregiver if the caregiver tries to leave
      • Continued crying after a caregiver has left
  • Pretend play: when a young child imitates adult activities and/or interactions [26]
    • Expected ages: starts around 15–18 months
    • Examples
      • The use of real or toy items to imitate activities
      • Symbolic play: the use of an item to represent other things
    • Benefits: enhances creativity and provides practice for social skills, emotional regulation, and language development [5]
  • Magical thinking: when thoughts are believed to affect change and nonrelated events are causally linked [5][6]
    • Expected ages: ∼4–5 years
      • Decreases with age
      • Some persistence into adulthood may occur. [5][27]
    • Examples
      • Assuming their actions cause unrelated events
      • Attributing emotions to an inanimate object
      • Believing that wishing for something causes it to come true
  • Imaginary companion: when a fictitious human, animal, or object is treated as if it were alive [28]
    • Expected ages: Preschool and young school-aged children [28]
    • Benefits are similar to those of pretend play. [28]

Common reactions to specific life eventstoggle arrow icon

Arrival of a sibling [29][30]

  • The arrival of a sibling can pose significant stress to a child, who may react with negative emotions (e.g., jealousy, anxiety, resentment, anger) and changes in behavior. Further typical reactions include:
    • Regression (psychiatry)
      • Bedwetting in a toilet-trained child
      • Finger or thumb sucking
      • Demanding help with eating
      • Wanting to drink from baby's bottle and/or wanting to breastfeed
      • Speaking like a baby
    • Changes in sleeping pattern
    • Violent behavior towards the sibling and/or caregivers (e.g., hitting, biting)
  • Counsel caregivers about the older child's possible reactions and advise them to:
    • Avoid other major changes at the same time as the anticipated arrival (e.g., moving houses, starting new kindergarten).
    • Organize caregiving support from other family and friends.
    • Spend alone time with the older child after the baby's arrival.
    • Encourage the older child to take part in the caretaking of their sibling and praise them for doing so.
    • Acknowledge the older child's negative emotions and reinforce their importance and sense of security.

Understanding of death [31]

  • A child's understanding of death depends strongly on their developmental age, personal experiences, and parental communication about death (including parents' spiritual and religious beliefs).
  • An adult understanding of death involves the comprehension of the following concepts:
    • Irreversibility: Death is permanent.
    • Universality: All living things will die eventually, including oneself.
    • Nonfunctionality: Upon death, all bodily processes end.
    • Causation: Death is caused by a breakdown of bodily functions.

Concepts of death at different ages

  • Infants and toddlers (0–2 years): no understanding of death
  • Preschoolers (3–5 years):
    • Typically perceive death as something temporary and reversible
    • May believe that they can influence death (“magical thinking”)
  • School-age children (6–12 years):
    • Typically know that death is irreversible and universal, may understand the concept of nonfunctionality
    • Often personify death (e.g., as a ghost)
    • Have a strong interest in death, and may feel anxious and fearful about their own death or the death of caregivers
  • Adolescents (13–18 years): typically have an adult understanding of death

Overview of abnormal developmenttoggle arrow icon

General principles

  • Early identification and treatment of developmental delay improve outcomes.
  • In children < 2 years old who were born prematurely, the chronological age must be adjusted for gestational age. [6]
  • Developmental surveillance should be performed at every well-child visit and includes: [32]
    • Inquiring if caregivers have any concerns
    • Reviewing and updating developmental history
    • Observing the child
    • Identifying risk factors for developmental delay
  • Developmental screening uses validated tools and should be used at set well-child visits or if there are concerns. [18][32]
    • Parent-completed tools can be used for initial screening.
    • If abnormal, directly administered tools are used for further evaluation.

Types of abnormal development [6][17][33]

Evaluation of abnormal pediatric development [6][18]

Management of abnormal pediatric development [18]

Anticipatory guidance for pediatric developmenttoggle arrow icon

  • Proactively discuss with caregivers ways of encouraging normal development, e.g.:
    • Initiate supervised tummy time early. [35]
      • Increase gradually based on the infant's interest level.
      • The target is 30 minutes spread out over the day.
    • Talk to and with the child. [36]
      • Describe everyday activities to the child.
      • Sing nursery rhymes.
      • Promote early exposure to books.
      • Point to and name everyday objects.
    • Actively play with the child, e.g.: [37]
      • Interact with reciprocal games like pat-a-cake, peek-a-boo, Simon says.
      • Make different faces with the child.
      • Demonstrate how to use age-appropriate toys or household items.
      • Introduce different objects of different textures, sizes, and colors.
      • Engage in role-playing.
  • Advise on adequate sleep, nutrition, and physical exercise to support development (see “Anticipatory guidance for children”).
  • Ensure caregivers know the expected developmental milestones for their child's age.
  • Advise caregivers to consult a healthcare professional early if they have development concerns, rather than waiting to see if the child will catch up. [20]

Reading, talking, singing, and playing with infants promotes normal early pediatric development. [36]

Referencestoggle arrow icon

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