Michael Levin argues that data from the study are consistent with a black/white IQ difference that is significantly genetic. Richard Lynn maintains that adoption by middle-class, white families has no effect on intelligence. Waldman, Weinberg, and Scarr respond to these criticisms and support the original conclusions. (SLD)

An analysis of intelligence quotient (IQ) in relation to head size was performed on about 14,000 children aged 4 and 7 years, almost equally divided by race (white and black) and sex. Correlation between head size (by inference, brain size), and IQ is established as a within-families correlation. (SLD)

This book focuses on topics germane to cognitive abilities viewed from a "minority psychology" perspective. The most contentious chapters concern test bias and heredity, with culture, socioeconomic status, and case viewed as the chief explanations for test score differences between social classes and racial and ethnic groups. The reviewer…

The egalitarian dogma, the belief that blacks and whites are genetically equal in cognitive ability, has been perpetuated through intimidation and pious thinking. Data on racial differences and the corruption of scholarship that causes them to be ignored are discussed. (SLD)

Swedish longitudinal studies of twins support Scarr-Salapatek's explanation of nature-nurture influences on intelligence. This model predicts more genetic variance in test results for advantaged than disadvantaged groups. Jensen's work, however, suggests equal amounts of variance among different social classes. (Author/CP)