Environmental Handicaps and Intellectual Development: Part Ii

S ummary . This article gives the comparative results of samples of West Indian and English 10 1/2–11‐year boys on a battery of perceptual and performance tests. These, together with the results on educational and verbal tests and assessments of background variables, were analysed, and a similar factor structure was obtained in the two groups. The deficit of West Indian boys varies considerably with different tests, being most marked for practical and some non‐verbal g tests (also for pure linguistic development), much less serious for educational attainments and for various perceptual abilities. Differences between urban and rural sub‐groups in the West Indian sample tend to replicate this pattern. Substantial correlations in both samples were obtained between test performance and assessments of the cultural stimulus provided by the home, and smaller ones with socio‐economic status and with purposeful‐rational home climate. Male influence in the home seems to be particularly associated with the development of more practical abilities. The implications of the research for testing the educational potential of West Indian immigrant children in Britain are discussed.