Child development is a very important part of psychology since our early development can greatly influence our future behavior and mental processes.
Prenatal influences on human development include genetics and teratogens (chemicals ingested by the mother that cause damage to the unborn infant). Many potentially harmful substances are filtered out by the placenta, but some are still able to pass through and impact the development of the fetus. A very common teratogen is alcohol, which can cause fetal alcohol syndrome. FAS causes children to have small, malformed skulls and mental retardation. Even moderate drinking can cause fetal alcohol effect, which tends to cause learning disabilities and behavioral problems. Other serious teratogens include cocaine and heroin, which can cause the unborn infant to become addicted. The withdrawal from these drugs can then cause serious health problems for the infant and even death. Genetics also highly influence our development by determining our learning abilities through memory and other structural components. Genetics can also cause mental retardation and problems such as crippling disorders. The full extent of genetic influence on child development is unknown, but researchers are making discoveries daily now that the genetic code has been decoded.
Babies are born with certain reflexes: The rooting reflex causes the baby to turn its head in the direction of anything that touches its cheek in an attempt to suck on it. The sucking reflex causes the baby to attempt to suck on anything placed near its mouth. The grasping reflex causes the baby to attempt to grasp anything placed on its palm or foot pad. The Moro reflex causes the baby to fling out its limbs and quickly retract them when startled. The Babinski reflex causes the baby to spread its toes whenever its feet are stroked.
A baby's senses are fairly well developed by the time it is born. Minutes after birth, a baby will attempt to turn its head to locate its mother's voice. A baby also possesses the same basic preferences in taste and smell as a fully developed human. In babies, the dominant sense is hearing, while older humans use vision as their dominant sense. Babies are born almost legally blond since they can only clearly see things 8-12 inches in front of them. Their vision improves to the normal level (barring any vision problems such as myopia) by the time they are a year old. Babies also appear to possess visual preferences as they enjoy looking at faces and face like objects more than anything else.
The motor development in babies occurs as their nerve cells connect with one another and become myelinated with a protein sheath. Most babies can roll over at about 6 months, stand at 9 months, and walk alone by 15 months. Although environment and parental encouragement could possibly have some effect on the development of motor skills, the effect, if any, is very slight.
Studies on monkeys by Harry Harlow showed that physical comfort is very important in child development. Baby monkeys given the choice of a wire frame milk-giving mother and a soft carpeted mother without milk chose the carpeted mother. He also noticed that the monkeys raised by the wire frame mother became more stressed and frightened than monkeys raised by real mothers when put into new situations. Deprivation from the mother tends to cause serious impediments to the child's development.
Another psychologist known as Mary Ainsworth researched the idea of infant attachment. 2/3 of babies have secure attachments and tend to explore in their parents' presence, but become distressed upon their departure. Babies with avoidant attachments (about 21 percent of the population) tend to resist being held and do not go to the parents for comfort upon their return. Babies with anxious/ambivalent attachments (about 12 percent of the population) tend to show stress when their parents leave but do not go to them for comfort upon their return.
Studies have also shown that parenting styles can seriously impact child development. Authoritarian parents who set strict standards and punish their child for breaking them tend to produce the best-behaved children. Children from such homes tend to distrust others and withdraw from peers. Permissive parents do not set clear guidelines for their children and any rules that are set change constantly. Children of such parents tend to have emotional control problems and dependency. Authoritative parents set guidelines for their children, but only ones that can be clearly explained and reasonable. Children from such homes perform well academically on average and are more socially capable.