Conceptual and linguistic biases in children's word learning.

Four studies examined the influence of essentialist information and perceptual similarity on preschoolers' interpretations of labels. In Study 1, 3-, 4-, and 5-year-olds were less likely to interpret 2 labels for animals as referring to mutually exclusive categories: when the animals were said to share internal, rather than superficial, properties and when the animals were perceptually similar rather than dissimilar. In Study 2, neither internal nor functional property information influenced 4-year-olds' interpretations of labels for artifacts. Studies 3 and 4 provide baseline data, demonstrating that the domain differences were not due to prior differences in children's lexical knowledge in the 2 domains. These results suggest that children have essentialist beliefs about animals, but not about artifacts, and that these beliefs interact with children's assumptions about word meaning in determining their interpretations of labels.