doi:10.1037/1076-8971.11.2.235
THIRTY YEARS OF RESEARCH ON RACE DIFFERENCES IN COGNITIVE ABILITY J. Philippe Rushton The University of Western Ontario Arthur R. Jensen University of California, Berkeley Theculture-only(0% genetic–100% environmental) and thehereditarian(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,gfactor of mental ability, heritability, brain size and cognitive ability, transracial adoption, racial admixture, regression, related life-history traits, human origins research, and hypothesized environmental vari- ables. 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). Section 1: Background Throughout the history of psychology, no question has been so persistent or so resistant to resolution as that of the relative roles of nature and nurture in causing individual and group differences in cognitive ability (Degler, 1991; Loehlin, Lindzey, & Spuhler, 1975). The scientific debate goes back to the mid-19th century (e.g., Galton, 1869; Nott & Glidden, 1854). Starting with the widespread use of standardized mental tests in World War I, average ethnic and racial group differences were found. Especially vexing has been the cause(s) of the 15-point Black–White IQ difference in the United States. In 1969, theHarvard Educational Reviewpublished Arthur Jensen’s lengthy article, “How Much Can We Boost IQ and School Achievement?” Jensen con- cluded that (a) IQ tests measure socially relevant general ability; (b) individual differences in IQ have a high heritability, at least for the White populations of the Unite…