The Raven Standard Progressive Matrices Test was administered to 356 5thand 6th-grade students to determine the effects of past experiences related to race, social class, and sex. All social class differences were significant, while a racial difference was found only in the lower class. No sex differences were significant. Relationships between the Matrices Test and other measures (both standard tests and family experiences) varied among the different race, class, and sex groups. This suggests that future research must not fail to consider race, class, and sex in its investigation of the usefulness of the Matrices Test, and, more generally, experiential influences on intelligence and school achievement.The biasing effects of characteristics such as social class have been acknowledged since Binet's work with intelligence testing (Binet & Simon, 1916). More recently, culture (Masland, Sarason, & Gladwin, 1958) and race (Dreger & Miller, 1960) have been added to social class as considerations of the ways in which the experience of particular groups of people will affect their performance on any given task. Culture-fair tests are thought to measure nonverbal (and hence noncultural) aspects of performance and thus to provide a closer estimate of the individual's native poarticle is based on an honors thesis submitted by the first author to the Department of Psychology, University of Maryland, for the baccalaureate degree. Marvin G.