Piagetian theory and the atypical case: an analysis of the developmental Gerstmann syndrome.

Abstract

This paper presents an analysis of a particular form of atypical cognitive development from the point of view of Piaget's normative developmental theory. Two 9-year-old boys are described who performed in the normal range on measures of IQ, language ability, and reading. The boys were unable, however, to acquire elementary numerical skills and also manifested other specific cognitive deficits associated with the Gerstmann syndrome. The results of additional testing on a battery of Piagetian tasks indicated that neither child had advanced to the Piagetian stage of concrete operations. These findings have implications both for Piaget's theory and for understanding the nature of the atypical development. Regarding atypical development, the findings indicate that children's acalculia is not an isolated deficit but rather that the general delay in the stage transition inhibited the children's development of numerical skills. With respect to Piagetian theory, the finding that the boys had not achieved numerical skills but had acquired reading skills suggests that whereas the acquisition of the former are closely linked to Piaget's stages of operational development, the acquisition of the latter are not directly dependent on stages of operational development.