Developmental analyses of two formal operational structures: Combinatorial thinking and conditional reasoning

Investigated developmental patterns for combinatorial thinking and conditional reasoning abilities and explored the possibility of an interrelationship between these formal operational structures in preadolescents and adolescents. 10 males and 10 females (IQ > 110) at each of the 5th-, 6th-, 7th-, and 8th-grade levels were given (a) 2 verbal and 1 quantitative combinatorial thinking tasks and (b) a 30-item conditional reasoning test (2-wk intertest interval). Analysis of variance for the verbal combinatorial thinking revealed that 7th and 8th graders scored significantly higher than 5th graders, and that male 6th graders scored higher than female 6th graders while female 7th graders scored higher than male 7th graders. Analysis of quantitative thinking scores also revealed a significant (positive) effect for grade level but no sex * grade level interactions. Conditional reasoning scores for 8th graders were also significantly higher than Ss' scores at any other grade level. These overall findings support Piaget's contention that formal operational structures emerge during early adolescence; however, the nonsignificant correlations between Ss' scores on the 2 types of tasks fail to confirm his contention of an integration of formal operational competencies during this period. Methodological problems with the Piagetian clinical approach are noted.