The discrepancy between middle-class and lower-class children's performance on IQ tests has been thought of as "cognitive deficit" or as "cognitive differences." This paper proposes another explanation--cognitive lag hypothesis--according to which the low IQ test scores of lower-class children are seen as due to the developmentally delayed…

Second generation, middle-class, Black youth and middle-class White youth completed the Stanford Binet, WISC-R, or the WAIS. Results indicated that Black youth exceeded the White sample mean on the Stanford Binet and the WISC-R. Previous intelligence differences may have reflected educational and socioeconomic differences. (Author/RC)