The author presents a discussion of certain portions of Arthur Jensen's controversial article. The general conclusion is that Jensen has not provided substantial evidence that there are differences in neural structure among children from different social or ethnic groups which are genetically determined. The reviewer reacts to Jensen's conclusion…

Disparities between European countries and the U.S. in terms of incidence and prevalence of mild mental retardation have become apparent. A model of intellectual performance that might explain disparities and predict future levels of occurrence of mild mental retardation is presented. Such explanations are relevant for theory and policy decisions.…