Variations in the amount and nature of early language to which
children are exposed have been linked to their subsequent ability (e.g.
Huttenlocher, Haight, Bryk, Seltzer & Lyons, 1991; Hart & Risley,
1995). In three computational simulations, we explore how differences
in linguistic experience can explain differences in word learning ability
due to changes in the development of semantic category structure.
More specifically, we manipulate the amount of language input,
sentential complexity, and the frequency distribution of words within
categories. In each of these simulations, improvements in category
structure, are tightly correlated with subsequent improvements in word
learning ability even when the nature of the input remains the same
over time. These simulations suggest that variation in early language
environments may result in differences in lexical proficiency by altering
underlying cognitive abilities like categorization.