A 60-page review of the scientific evidence, some based on state-of-the-art magnetic resonance imaging (MRI) of brain size, has concluded that race differences in average IQ are largely genetic.
The lead article in the June 2005 issue of Psychology, Public Policy and Law, a journal of the American Psychological Association, examined 10 categories of research evidence from around the world to contrast “a hereditarian model (50% genetic-50% cultural) and a culture-only model (0% genetic-100% cultural).”
The paper, “Thirty Years of Research on Race Differences in Cognitive Ability,” by J. Philippe Rushton of the University of Western Ontario and Arthur R. Jensen of the University of California at Berkeley, appeared with a positive commentary by Linda Gottfredson of the University of Delaware, three critical ones (by Robert Sternberg of Yale University, Richard Nisbett of the University of Michigan, and Lisa Suzuki & Joshua Aronson of New York University), and the authors’ reply.
“Neither the existence nor the size of race differences in IQ are a matter of dispute, only their cause,” write the authors. The Black-White difference has been found consistently from the time of the massive World War I Army testing of 90 years ago to a massive study of over 6 million corporate, military, and higher-education test-takers in 2001.