This report contains a series of studies which represent ongoing research of six investigators, who seek to elucidate through empirical studies the psychological characteristics of culturally disadvantaged children. The chief aim has been to make comparative analyses of abilities and learning characteristics of children from intact subpopulation groups that differ markedly in the degree of school success typically achieved. The studies focus on: a two-level theory of mental abilities; the organization of abilities in preschool children; level I and level II performance in low and middle socioeconomic status (SES) elementary school children; relationship of the "Draw-a-Man" Test to level I and level II; comparison of "culture-loaded" and "culture-fair" tests; social class differences in free recall of categorized and uncategorized lists; mental elaboration and learning proficiency; ethnicity-SES and learning proficiency; and, elaboration training and paired associate learning efficiency in children. Appendixes contain some of the test forms used. (RJ)