The poor performance of Black children on IQ tests and in school has been hypothesized to arise from (a) genetic racial differences or (b) cultural/environmental disadvantages. To separate genetic factors from rearing conditions, 130 Black and interracial children adopted by advantaged White families were studied. The socially classified Black adoptees, whose natural parents were educationally average, scored above the IQ and the school achievement mean of the White population. Biological children of the adoptive parents scored even higher. Genetic and environmental determinants of differences among the Black and interracial adoptees were largely confounded. The high IQ scores of the socially classified Black adoptees indicate malleability for IQ under rearing conditions that are relevant to the tests and the schools.(PsycINFO Database Record (c) 2016 APA, all rights reserved)