Ethnic Differences in Children's Intelligence Test Scores: Role of Economic Deprivation, Home Environment, and Maternal Characteristics

We examine differences in intelligence test scores of black and white 5-year-olds. The Infant Health and Development Program data set includes 483 low birthweight premature children who were assessed with the Wechsler Preschool and Primary Scale of Intelligence. These children had been followed from birth, with data on neighborhood and family poverty, family structure, family resources, maternal characteristics, and home environment collected over the first 5 years of life. Black children's IQ scores were 1 SD lower than those of white children. Adjustments for ethnic differences in poverty reduced the ethnic differential by 52%. Adjustments for maternal education and whether the head of household was female did not reduce the ethnic difference further. However, differences in home environment reduced the ethnic differential by an additional 28%. Adjustments for economic and social differences in the lives of black and white children all but eliminate differences in the IQ scores between these two groups.