Preceded by three studies of preschool children, this research compared the thinking abilities of 5-year-old white and black children in relation to certain environmental factors. All of the 2413 children were chosen to conform with the earlier studies by having approximately one-fourth with mothers having graduated from college, one-half graduated from high school, and one-fourth with ninth grade education or less. A questionnaire covering the environmental influences in the life of the child was asked of each mother, and the questions were analyzed to determine the relationship to the thinking ability of the children. Some of the findings were: marital status is more related to performance in black children than in white; father's occupation has a more differentiating effect in blacks than in white in the semantic context; age is more effective for spatial abilities than for language; sex contributes little at this age level; race is more effective for language-based performance than for spatial relations; white children with higher scores seem to have more permissive, more concerned homes; black children with high performance seem to have highly structured homes with concerned, striving adults. (LH)