A. Age 0-2 Months
Physical Development
Infants regain or exceed birthweight by 2 wk of age and should grow at approximately 30 g (1 oz)/day during the 1st mo.
Limb movements consist largely of uncontrolled writhing, with apparently purposeless opening and closing of the hands.
Smiling occurs involuntarily.
Eye gaze, head turning, and sucking are under better control and thus can be used to demonstrate infant’s perception and cognition.
An infant’s preferential turning toward the mother’s voice is evidence of recognition memory.
Cognitive Development
Infants appear to seek stimuli actively, as though satisfying an innate need to make sense of the world.
Infants can recognize facial expressions (smiles) even when they appear on different faces.
Infants at 2 mo of age can discriminate rhythmic patterns in native vs non-native language.
Emotional Development
The infant is dependent on a trusted adult to meet the infant’s urgent needs. The first of Erikson’s psychosocial stages is basic baby-mother bonding.
Crying occurs in response to stimuli that may be obvious (a soiled diaper), but are often obscure.
Crying normally peaks at about 6 wk of age, when healthy infants may cry up to 3 hr/day, then decreases to 1 hr or less by 3 mo.
Differing feeding schedules produce differing reactions. Hunger generates increasing tension
Implications for Parents
Success or failure in establishing feeding and sleep cycles, infant issues (colic) occur during this period. When everything go well parents sense a complete bonding.
Mild postpartum depression that affects many mothers passes. Only 10% of postpartum women progress to depression.
The pediatrician may be the first professional to asist the depressed mother.
B. Age 2-6 Months
At about 2 mo, voluntary (social) smiles and increasing eye contact makes a change on parent-child relationship by a sense of being loved reciprocally.
Infant’s range of motor and social control, cognitive development increases resulting in strong mutual attachment and enjoyment.
Physical Development
Between 3 and 4 mo of age, the rate of growth slows to approximately 20 g/day.
By 4 mo, birth weight is doubled.
Infants can begin to examine objects in the midline and manipulate them with both hands voluntarily.
With increasing control of movements the quality of spontaneous movements also changes.
Infants can hold their heads steady.
Visual system maturates, they can gaze at things.
They can begin taking food from a spoon.
In this period, infants achieve regular sleep-wake cycles.
Cognitive Development
At 4 mo of age, infants become interested in a wider world.
During feeding, infants no longer focus exclusively on the mother, may turn around in the mother’s arms, preferring to face outward.
Infants learn voluntary muscle movements.
They explore their own bodies.
They also have a a sense of self, separate from the mother. The sound, smell, and feel of the mother sometimes appear promptly in response to crying, but sometimes do not. This is the first stage of personality development.
Emotional Development and Communication
The primary emotions of anger, joy, interest, fear, disgust, and surprise appear as distinct facial expressions.
Initiating games (facial imitation, singing, hand games) increases social development.
Such face-to-face behavior reveals the infant’s ability and is the first step in the development of communication.
Implications for Parents
Most parents excitedly report that they can hold conversations with their infants, taking turns vocalizing and listening.
Parents can be reassured that responding to an infant’s emotional needs can not spoil him or her.
Age 6-12 Months
6-12 mo old infants develop wills and intentions, characteristics, show advances in cognitive understanding and communication, achieve new skills
Physical Development
By the 1st birthday, birthweight has tripled, length has increased by 50%, and head circumference has increased by 10 cm.
They achieve the ability to sit unsupported (6-7 mo) and to pivot while sitting (around 9-10 mo)
Many infants begin crawling and pulling to stand around 8 mo.
Some walk by 1 yr.
Tooth eruption occurs
Cognitive Development
The 6 mo old infant discovers his hands. At first, everything goes into the mouth. In time, novel objects are picked up, inspected, passed from hand to hand, banged, dropped, and then mouthed. Each action represents a nonverbal idea about what things are for.
The complexity of an infant’s play, how many different schemata are brought to bear, is a useful index of cognitive development at this age.
A major milestone is the achievement at about 9 mo of object permanence (constancy), the understanding that objects continue to exist, even when not seen.
Emotional Development
Infants demonstrate stranger anxiety.
Infants who have been sleeping through the night for months begin to awaken regularly and cry.
Use of the 2-spoon method of feeding (1 for the child and 1 for the parent), finger foods, and a high chair with a tray table can avert potential problems.
Communication
Infants at 7 mo of age are adept at nonverbal communication.
Around 9 mo of age, infants become aware that emotions can be shared between people; they show their happy feelings.
Between 8 and 10 mo of age, babbling takes on a new complexity, with many syllables (“ba-da-ma”) and inflections that mimic the native language.
Picture books provide an ideal context for verbal language acquisition.
Implications for Parents
With the developmental reorganization that occurs around 9 mo of age, previously resolved issues of feeding and sleeping re-emerge.
Parents should be encouraged to plan ahead for separations.
Infants’ wariness of strangers often makes the 9 mo examination difficult.