The role of developmental change and linguistic experience in the mutual exclusivity effect

Given a novel word and a familiar and a novel referent, children have a bias to assume the novel word refers to the novel referent. This bias - often referred to as "Mutual Exclusivity" (ME) - is thought to be a potentially powerful route through which children might learn new word meanings, and, consequently, has been the focus of a large amount of empirical study and theorizing. Here, we focus on two aspects of the bias that have received relatively little attention in the literature: Development and experience. A successful theory of ME will need to provide an account for why the strength of the effect changes with the age of the child. We provide a quantitative description of the change in the strength of the bias across development, and investigate the role that linguistic experience plays in this developmental change. We first summarize the current body of empirical findings via a meta-analysis, and then present two experiments that examine the relationship between a child's amount of linguistic experience and the strength of the ME bias. We conclude that the strength of the bias varies dramatically across development and that linguistic experience is likely one causal factor contributing to this change. In the General Discussion, we describe how existing theories of ME can account for our findings, and highlight the value of computational modeling for future theorizing.

Metacognitive developments in word learning: Mutual exclusivity and theory of mind

This project examined the flexibility with which children can use pragmatic information to determine word reference. Extensive previous research shows that children choose an unfamiliar object as referent of a novel name-the disambiguation effect. We added a pragmatic cue indirectly indicating a familiar object as intended referent. In three experiments, preschool children's ability to take this cue into account was specifically associated with false belief understanding and the ability to produce familiar alternative names (e.g., rabbit, animal) for a given referent. The association was predicted by the hypothesis that all three tasks require an understanding of perspective (linguistic or mental). The findings indicate that perspectival understanding is required to take into account indirect pragmatic information to suspend the disambiguation effect. Implications for lexical principles and sociopragmatic theories of word learning are discussed.