Comparison in the development of categories

Recent research on children's word learning has led to a paradox. Although word learning appears to be a deep source of insight into conceptual knowle dge for children, preschoolers often categorize objects on the basis of sha llow perceptual features such as shape. The current studies seek to resolve this discrepancy. We suggest that comparing multiple instances of a catego ry enables children to extract deeper relational commonalities among catego ry members. We examine 4-year-olds' categorization behaviors when asked to select a match for a target object (e.g., an apple) between a perceptually similar, out-of-kind object (e.g., a balloon) and a perceptually different category match (e.g., a banana). Children who learn a novel word as a label for multiple instances of the category are more likely to select the categ ory match over the perceptual match. Children who learn a label for only on e instance are equally likely to select either alternative. This effect is present even when individual target instances are more perceptually similar to the perceptual choice than to the category choice. We conclude that str uctural alignment processes may be: important in the development of categor y understanding.