Developmental Milestones

By Hillary Kruger, M.D. (Co-director of the division of behavioral and developmental pediatrics at Maimonides Medical Center in Brooklyn, NY) for Your Baby Today

The first year of an infant's life is filled with tremendous growth and development. There is a range of what constitutes normal acquisition of the various milestones. Below you will find a summary of social-emotional growth, the acquisition of language, and the development of fine and gross motor skills during the first year of life.

Progress varies among babies, so please consult your pediatrician for further information about these milestones. A great resource to have on hand is Dr. Steven P. Shelov's book, Your Baby and Child.

Social-Emotional Development
Newborn babies look about with a glassy gaze at a brand new world. Early on babies show a preference for looking at human faces. The ideal distance for a baby to focus during the first couple of months is about eight to twelve inches -- the distance between your baby and your face when you hold the baby in the crook of your arm.

Jean Piaget, noted psychologist, characterized the early months as the "sensorimotor phase," which aptly describes the activities of the 1- to 3-month-old child who explores the world through his or her mouth. The spontaneous, random smile of the 1-month-old child develops into the socially responsive smile at around 2 months of age. The baby is learning to recognize familiar faces and is eager to greet them. The 4-month-old baby is able to sustain longer periods of social contact and can express a fuller repertoire of pleasure and displeasure.

From about 6 months of age onwards, babies begin to develop the Piagetian concept of "object permanence" (baby has a more fully developed mental image of people and objects that continue to exist even when the person or object is not currently visible). A baby knows when parents leave the room, and now the baby will more actively seek them when they are not present.

Becoming wary of unfamiliar people, or of friends and relatives who are not often seen, typically begins around 8 to 10 months of age. The term that has been coined for this wariness is "stranger anxiety," and you may want to warn visitors not to rush to hug the baby, but to give her time to warm up to them.

As the tension around separation often intensifies between 6 and 12 months of age, peek-a-boo becomes the perfect game for playing out some of these feelings. Babies become excited by the disappearance and reassuring reappearance of a familiar face. As parents and other important caregivers come and go throughout the day, it becomes particularly important to let your baby know when you are going out and that you will come back soon. Sneaking out in the hope that this will lessen the pain of separation often backfires (suddenly disappearing may make baby anxious).

From about 8 months on, babies can enjoy learning to play hide-and-seek. You can hide a small toy under a cloth and watch your baby gleefully snatch back the cloth to discover the hidden treasure. At around 1 year of age, a baby will enjoy games that are reciprocal, such as rolling a ball back and forth with a partner. Babies enjoy pointing to objects of interest and focusing their parents' attention on an item of interest to them.


Language
Speech and language development in the first year of life typically follows an orderly progression from grunting and sucking sounds in the newborn to the emergence of a first word at 1 year of age. By 2 months of age, the baby will listen to voices and is beginning to coo. A 3- to 4-month-old will pay attention to music and is beginning to make "ooh" and "ah" sounds. By 6 months, baby will make single consonant-vowel sounds like "ba," "ma," and "ga," progressing into multi-syllable babbling by 9 months of age. Around 9 months of age, babies will begin to say "mama" and "dada" in a non-specific way. By age one, "mama" really means "mother," and "dada" really means "father." It is a little easier to say "dada" than it is to say "mama," so mothers should not feel rejected if "dada" is uttered first. At around 1 year of age babies should be using a word to name him- or her-self, parents, family members, and other caregivers. For example, something like "ba" for baby. By 1 year, a baby can understand a simple command when it is accompanied by a gesture, such as "pick up your toy" or "get your shoes."


Fine Motor and Adaptive Skills
Starting from within the womb, a fetus has been observed to suck on his or her fingers. A newborn's hands are typically held closed in tight fists. The fascination with the hands continues in early life, and beginning around 2 months of age, babies often enjoy watching as they wave their fingers. Between 2 and 4 months of age, a baby will relax the hands more and more. By 4 months of age, babies will actively reach for toys and hold them. The ability to voluntarily let go of a held object doesn't develop until close to 12 months of age. An infant will often eagerly reach for a small item, and once it is captured in that chubby little hand, it will be "out of sight, out of mind."

By 6 months of age, babies can use a raking grasp to pick up a toy, and then they can pass it from one hand to the other. At this age, babies are learning how to bring their hands together for midline play. From around 9 months on, babies are beginning to separate the thumb from the rest of the fingers. They can pick up an item with a scooping motion between the thumb and index finger. A 9-month-old child will more actively explore a toy, turning it over and over and poking it with one finger. A 9- to 10-month-old child may begin to drink from a cup with assistance and a 1-year-old child can begin to use a spoon. The major fine motor milestone that is achieved at around 12 months of age is the emergence of the mature pincer grasp -- that is, picking up a small item such as a raisin neatly between the thumb and forefinger with a precise movement.


Gross Motor Skills
A newborn should move both arms and legs equally and symmetrically. Newborns typically have a flexed, curled up position and they like to be swaddled securely. Newborns have primitive reflexes that usually begin to disappear at around 3 to 4 months of age. One reflex that is very noticeable is the Moro or "startle" reflex in which the baby's hands will reach out and then will come back into the body upon a sudden change in the baby's position.

By 3 months of age, a baby will be able to lift his head and chest up off a flat surface when lying on his tummy. The American Academy of Pediatrics recommends placing infants on the back or side when they go to sleep to reduce the risk of "sudden infant death syndrome." When the baby is awake, it is good exercise for her to have some tummy time, so she can strengthen her arms and head and neck muscles. By 4 months of age, a baby should have good head control when she is pulled up to a sitting position.

By 6 months of age, a baby should be able to sit with the hands out in front for support (tripod sitting). The baby should be sitting unassisted by 8 months of age. By 9 to10 months of age, a baby is pulling herself up to stand and may be starting to take some steps holding on (cruising). By the first birthday, a baby can usually walk with one hand held. About 50% of children can walk without help by one year of age, and the rest will have learned to walk unassisted by 16 to 18 months.