A. R. Jensen's hypothesis concerning genetically-determined differences in intelligence between North American blacks and whites is summarised. Problems involved in the application of heritability statistics to IQ data are discussed. The concept of “intelligence” is reviewed from a cross-cultural perspective, and an alternative model of potential, competence and performance is proposed. Finally, the questions of scientific freedom and social responsibility are touched upon, and the implications of the great debate for scientists and educators discussed.
