A rose by any other name: Preschoolers' understanding of individual identity across name and appearance changes

Abstract

One of the major achievements of early cognitive development is the ability to understand that an object's individual identity can remain stable while various properties of the object change. Previous research has indicated that preschoolers determine individual identity using properties such as proper name and appearance. These results contrast with recent theory and research showing preschoolers' ability to go beyond variable/external properties in their judgments concerning category membership. Previous results may also be due in part to the methodologies employed. We therefore conducted three experiments investigating the effect of changes in proper name or appearance on children's judgments of individual identity of animals, using an alternative methodology based on the theory of psychological essentialism. Pictures of familiar animals (e.g. dogs) that were given specific behavioural (primarily) properties chosen to be both stable in nature and highly individuating were shown to 4-year-olds, 5-year-olds and adults. Name or appearance was then altered and participants judged whether the animal's behaviour had also changed. Judgments of stability in behaviour were taken to correspond to judgments of stability in individual identity. By age 4 most children consistently judged that stable properties were unaflected by changes in name and appearance, suggesting that preschoolers may possess a better understanding of individual identity than previously thought. These results are discussed in terms of the relation of identity understanding to conceptual development.