Environmental Factors Affecting Human Development, Before and After Birth

The relationship of socioeconomic factors to pregnancy experience and later neuropsychiatric functioning was investigated by a series of retrospective and anterospective epidemiologic studies. The studies demonstrated an increased amount of brain damage in the lower socioeconomic strata, where a higher incidence of complications of pregnancy and a greater number of babies with low birth weights are found. In 992 infants examined at 40 weeks of age, pregnancy experience, birth weight and later physical status were the only major factors which could explain group differences in developmental quotients. The studies further indicated that the relatively small amount of variability found in infancy could be explained largely by the presence of damage to the central nervous system, and supported the view that at this period of life social factors affect the psychologic level of integration primarily through biologic mechanisms. Later, during the preschool period, the direct influence of the sociocultural forces on the psychologic performance becomes manifest.