Causal supports for early word learning

What factors determine whether a young child will learn a new word? Although there are surely numerous contributors, the current investigation highlights the role of causal information. Three-year-old children (N = 36) were taught 6 new words for unfamiliar objects or animals. Items were described in terms of their causal or noncausal properties. When tested only minutes after training, no significant differences between the conditions were evident. However, when tested several days after training, children performed better on words trained in the causal condition. These results demonstrate that the well-documented effect of causal information on learning and categorization extends to word learning in young children. Young children are excellent word learners. We have made great progress toward understanding how and why this is so. In particular, we know a lot about when and how children (a) isolate words from ongoing speech, (b) map words to their intended referents, and (c) extend words appropri-ately. Questions remain, however, regarding the factors that determine whether, and how rapidly, a particular word becomes a lasting component of a child’s lexicon. Clearly, young children learn some words before others (e.g., Fenson et al., 1994; Nelson, 1973). Both the frequency and schedule of exposure help deter-mine order of acquisition (e.g., Childers & Toma-sello, 2002; Hollich et al., 2000). The perceptual and ⁄or conceptual accessibility of referents also probably contributes (e.g., Gentner, 1982; Rosch, Mervis, Johnson, & Boyes-Braem, 1976). Another potential factor is the type of knowledge a child has about the items being labeled. We propose that words applied to referents with known conceptual properties will be more readily acquired than will words applied to referents for which conceptual properties are unspecified. Well-documented principles of memory suggest two reasons to believe that this should be so. First, focused attention facilitates memory (e.g., Craik