Proposes a theoretical model of cognitive development and applies this model to the secondary analysis of two large-scale studies which focus on the acquisition of formal operational schemata by adolescents in the United States and Israel. Results support the "unity" hypothesis of cognitive development that the various schemata of formal…

Investigated were gender-related differences in the relationship between the development of formal reasoning skills and learning interests during the early adolescent stage. Results indicated that adolescent boys appeared to develop patterns of formal reasoning before their female classmates. Differences in subject preferences were also found. (CW)