Intellectual differences in Negro and white mental defectives

Scores of 199 Southern Negro and white children whose Full Scale IQ was 69 or below were compared for the verbal and performance tests of the WISC. A multivariate test of the hypothesis of no mean racial differences resulted in the hypothesis being rejected for both sexes. A discriminant function determined from the tests classified 73% of the original Ss into their correct racial group and 63% of a cross-validation sample of 141. Examination of the function weights and test mean differences yielded the conclusion that while the whites had the typical pattern of intellectual performance found in other studies with retardates, the score pattern for Negroes resembled that of gifted children in that their verbal test scores were generally higher than their performance test scores. Implications of this finding for diagnostic and educational procedures are mentioned.

Intellectual structure of Southern Negro children

In the 1950's the WISC was given by the same examiner to a selected sample of 84 Negro children in each of five Southern states. Ages which ranged from 5 yr., 7 mo., to 12 yr., 6 mo., and sexes were equally distributed within each state. Analysis of the data showed that the Verbal IQ was significantly higher ( p = .01) than the Performance IQ for both sexes, all ages, and all but one location. There were few sex differences. Except for its influence on the factor structure of the 12 verbal and performance tests, age was not an interesting classification of the data. In all, geographical groups differed much more in WISC performance than did age or sex groups. This is consistent with strong regional differences in Negro intellectual performance apparent from a review of previous studies.