What conditions foster or constrain children's category-based induction? This study examined the role of language, specifically the scope of noun phrases used to convey novel property information. We focused on generic noun phrases, which are especially common in child-directed speech and have been argued to play an important role in the growth of category knowledge. In Study 1, 4-year-olds and adults were taught novel properties about familiar categories, using 1 of 3 types of wording: a generic noun phrase (e.g., "Bears like to eat ants"), a universally quantified noun phrase (e.g., "All bears like to eat ants"), or an indefinite plural noun phrase (e.g., "Some bears like to eat ants"). Study 2 was a follow-up study with adults using a more sensitive task. Results indicated sensitivity to type of wording among both preschoolers and adults, with "all" eliciting the most inferences, "some" eliciting the fewest inferences, and generics in between "all" and "some." However, children made fewer category-based inferences from generics than did adults. Together, these studies suggest that (a) preschool children as well as adults distinguish generics from both "all" and "some," and (b) age differences exist in the interpretation of generic noun phrases.
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