Physical development during early years
Physical growth is rapid during infancy. Assuming good nutrition, infants almost triple in weight and increase in body length by about one-third during the first year alone. Although infants are capable of eating immediately, they have limited capacity for what they can consume at one time-their stomachs will not hold very much. They compensate for this by eating small amounts frequently, about 2.5 to 4 hours.
At birth, babies have a little ability to regulate their own temperature; in fact, they can’t maintain a normal body temperature by themselves until they are about eight or nine weeks old. So, it’s important to keep them warm- but not too warm!
Reflexes: At birth newborns possess several simple reflexes – inherited responses to stimulation in certain areas of the body. If these reflexes are present, the baby’s nervous system is assumed t be intact and working normally; if they are not, this is often a sign that something is seriously wrong. One such reflex, Moro reflex, is triggered by a loud sound or a sudden dropping back of the infant’s head. It involves a series of actions in which the baby first throws out his or her arms, then fans his or her fingers and lets out a cry before bringing the arms back over his or her chest.
Another is the palmar grasping reflex, which is elicited by pressing or stroking the palms of the newborn’s hands. The baby closes its hands and holds tight; in fact, infants can be lifted up from a flat surface by their grip. This reflex might well be useful in helping a baby cling to its mother as mother moves about.
Babies also possess a rooting reflex, in which stroking the baby’s check cause the baby to turn toward the stimulation and move its lips and tongue, and a sucking reflex, involving a combination of pressure and suction.
Locomotors Development: Infants have limited ability to move around at birth. This situation changes quickly, however, and within a few months they become quite mobile. Within about five to ten months, babies can sit and crawl; and most can begin to walk by the time they are fourteen or fifteen months old. Motor development proceeds from the head towards the limbs so that at first babies can hold up their head, then their chest, then sit, and so on. It’s important to keep in mind that the ages described are merely averages. Departures from them are of little importance unless they are quite extreme.
After the initial spurt of the first year, the rate of physical growth slows considerably; both boys and girls gain about 2 to 3 inches and 4 to 7 pounds per year. The rate accelerates during adolescence, when both sexes experience a growth spurt lasting about two years. These outward changes are accompanied by important inner ones, too. For instance, the brain expands rapidly through the first eighteen months of life, reaching more than half of the adult brain weight by the end of this period; by the time children are only five years old, the brain almost full-sized. During this period there is a rapid growth of dendrites and axons within the brain and glial cells, which supply nutrients to neurons, remove waste materials, and produce the myelin sheath that speeds neural impulses, increase rapidly in number.
Interestingly, motor development does not seem to be a function solely of maturation; cross-cultural studies indicate that it can be speeded or slowed by various child-rearing practices.
Perceptual Development: Studies based on this reasoning have found that newborns can distinguish between different colors, odors, taste. Moreover, infants as young two or three days have been found to show differential patterns f sucking patterns of sucking in response to what seems to be quite subtle differences in the sounds of human speech. Even at this tender age, infants show more vigorous sucking to words that are spoken with changing patterns of stress- for instance, “mama” versus “mama”- than to the same words when they are spoken with a constant pattern of stress. Infants as young as three days old will turn their eyes and heads in the direction of a sound. One sound to which infants are especially attentive is- not surprisingly- that of their own names.
Perhaps most surprisingly of all, newborns can tell the difference between the sound of their own cry and that of another newborn infant. That they can do so is indicated by the results of the research conducted by Dondi, Simion and Caltran. These researchers observed infants only one to three days old while they were exposed either to the sound of their own prerecorded cry, or to the crying of another infant of same age. This was done when both the infants were awake and alert, and when they were sleeping. Both the infant’s facial expression and their amount of sucking on a pacifier were observed both before the sounds were presented and while they were present. Results were clear; both when awake and sleeping, the infants showed greater responsiveness to the sound of another infant crying than to sound of their own crying.
Infants also show impressive abilities with respect to recognizing form or pattern. Although they can’t see very clearly at birth, they show marked preferences for patterns and contrast in visual stimuli. A research done by Fantz(1961) showed babies six months old a variety of visual patterns. By observing how long they looked each, he determined that the babies had a clear preference for patterned as opposed to plain targets and that they seemed to prefer the human face all over all other stimuli tested. Later research indicated that recognition of faces may develop even earlier. By two months of age, infants prefer a face with features in normal locations over one with scrambled features.
Many mothers and fathers have the impression that their newborns can recognize them soon after birth. Even infants two days old can distinguish their mother’s face from the face of a female stranger.
Thus, infants not only develop physically, but also perceptually as change in their body movements and perception takes place as they grow older.