The ability for dimensional analysis in preschool and retarded children: evidence from comparison, conservation, and prediction tasks

Previous findings of a developmental trend from holistic to analytic modes of processing yield to two possible interpretations—the ability to analyze into dimensions increases with age, or a production deficiency for the strategy of analyzing decreases with age. In the three studies reported here an attempt is made to elucidate which of these interpretations is the more correct by investigating the performance of preschoolers and retarded children in three tasks, all of which require dimensional analysis. The three tasks involve (a) same-different comparisons of selected dimensions of stimuli, (b) judgments of whether dimensions are conserved through transformations of objects, and (c) predictions of the outcomes of transformations that selectively modify dimensions of objects. Normal 3-year-old children and mildly retarded preadolescents make many errors on all three tasks and the patterns of these errors are predictable from holistic processing. Older groups of normal preschoolers, 4.5 to 5 years old, perform very well on the tasks, although they show some hints of remaining analytic deficits. It seems likely that the ability to analyze does undergo development in the preschool years, but that the production-deficiency interpretation also has merit, particularly for explaining developmental trends within the elementary school range.