Thirty years of research on race differences in cognitive ability

The culture-only (0% genetic-100% environmental) and the hereditarian (50% genetic-50% environmental) models of the causes of mean Black-White differences in cognitive ability are compared and contrasted across 10 categories of evidence: the worldwide distribution of test scores, g factor of mental ability, heritability, brain size and cognitive ability, transracial adoption, racial admixture, regression, related life-history traits, human origins research, and hypothesized environmental variables. The new evidence reviewed here points to some genetic component in Black-White differences in mean IQ. The implication for public policy is that the discrimination model (i.e., Black-White differences in socially valued outcomes will be equal barring discrimination) must be tempered by a distributional model (i.e., Black-White outcomes reflect underlying group characteristics).