Longitudinal course of measured intelligence in preschool children of different social and ethnic backgrounds.

Abstract

The longitudinal course of measured intelligence in white middle-class and Puerto Rican working class children was examined at three and at six years of age. Findings suggested that stability in IQ over this time period was characteristic of both groups, with greater stability manifested by the Puerto Rican than by the middle-class children. No evidence for deterioration of IQ with age in the disadvantaged group was found. The data are considered in relation to problems of the stability of IQ and its utility in the assessment of the effects of compensatory education programs.