Social class, as reflected in socioeconomic status (SES), has such a profound influence on all aspects of performance that it is perhaps the most powerful predictor of academic achievement. Intelligence quotient (IQ) tests in one form or another have been used for quantitative assessment of academic ability since Alfred Binet first developed the concept of IQ in 1904 to help identify slow learners for placement in special curricula. Yet, children of high SES families generally have higher IQ scores than low SES children. Therefore, obtaining fair assessments of academic ability in minority children, a disproportionate number of whom are socially disadvantaged, is wrought with difficulties. Much has been written to explain why more affluent school children do better than their disadvantaged peers. The most frequently cited factors are childbearing practices that focus on discipline and language. In general, however, research results have been confusing and sometimes contradictory. Raven's Colored Progressive Matrices Scale (CPM) was developed as a culture-fair test of cognition in children. A relatively nonverbal test of spatial analogues, the CPM has been considered a panacea by some. However, a careful review of the literature reveals that high SES children generally score significantly higher on the CPM than low SES children. (MCK)