Enhancing academic performance by strengthening class-inclusion reasoning.

Class inclusion is an early form of abstract thought that requires logical rather than perceptually based inferences plus an appreciation of part-whole relationships (B. Inhelder and J. Piaget, 1959/1964). The authors randomly assigned 2 groups of first graders who were having academic difficulties to be instructed on either class inclusion or phonics. Results showed a significant linear relation between individual children's mastery of class inclusion and their scores on the Cognitive Abilities Test Form 6 (D. F. Lohman and E. P. Hagen, 2001) verbal and quantitative measures of reasoning. The authors also found a significant linear relation between mastery of class inclusion and improvement in report card marks issued by teachers who were blind to the children's group assignment.