Sociologist Robert Gordon has analyzed black-white differences in crime and concluded that virtually all of the difference in the prevalence of black and white juvenile delinquents is explained by the IQ difference, independent of the effect of socioeconomic status. The only reliable indicator from the NLSY that lets us compare criminal behavior across ethnic groups is the percentage of young men who were ever interviewed while incarcerated.The figure below shows the standard comparison, before and after controlling for cognitive ability. Among white men, the proportion interviewed in a correctional facility after controlling for age was 2.4 percent; among black men, it was 13.1 percent. This large black-white difference was reduced by almost three-quarters when IQ was taken into account. The relationship of cognitive ability to criminal behavior among whites and blacks appears to be similar. 40 As in the case of other indicators, we are left with a nontrivial black-white difference even after controlling for IQ, but the magnitude of the difference shrinks dramatically.A more recent paper by Gordon (Everyday life as an intelligence test: Effects of intelligence and intelligence context. Intelligence, 24, 203-320.) confirms his results for juvenile delinquency and extends them to adult criminality.
[The Bell Curve, pp. 338-339; two papers by Robert Gordon are cited:
Gordon, R. A. 1987. SES versus IQ in the race-IQ-delinquency model. International J . of Sociology and Social Policy 7:30-96.
Gordon, R. A. 1976. Prevalence: The rare datum in delinquency measurement and its implications for the theory of delinquency. In The Juvenile Justice System. M. W. Klein (ed.). Beverly Hills, Cal.: Sage Publications, pp. 201-284.]
What explains racial differences in crime?
As we've seen, not testosterone. A much better candidate for explaining racial differences in criminality: racial differences in intelligence. Robert Gordon demonstrated decades ago that simply controlling for IQ eliminates almost the entire black-white gap in juvenile delinquency, and Murray and Herrnstein similarly find IQ explains most of the black-white difference in incarceration rates: