The interrelationships between aptitude test performance and certain demographic-cultural variables were investigated, as well as the relationship between these variables and the aptitude test factor content. Five test batteries were administered to groups of approximately 1,900 subjects each. Multiple regression analyses indicated that there were significant interaction effects for six of the selected tests. The relationships between the cultural variables combined and each aptitude test were significant for all tests. Significant net relationships of race, educational level, and geographic area were found with a majority of tests, although wide differences were found among aptitude tests in their sensitivity to demographic-cultural influences. Race appeared to be related to tests in most factor areas, with its highest relationship in the mechanical area, whereas education, which had the lowest relationships with the mechanical area, had the highest relationships with verbal, numerical, and reasoning factors. No discernible trend was noted for geographic area. (Author/BH)