Analysis of Performances by Normals and Retardates on Piagetian Reasoning Assessments as a Function of Verbal Ability

Criticism has been addressed to the Piagetian method for assessment of cognitive development because of the technique's dependence on verbal report. In the present study a battery of 29 reasoning assessments and the appropriate form of the Wechsler scales were administered to 75 normals and 75 retardates. Analyses of covariance were performed to determine the effect of language development on cognitive development. In general, results support Piaget's contention that cognitive development is not totally dependent on concurrent language development.