Children's interpretation of generic noun phrases.

Generic utterances (e.g., Cows say 'moo') have 2 distinctive semantic properties: (a) Generics are generally true, unlike indefinites (e.g., Bears live in caves is generic; I saw some bears in the cave is indefinite), and (b) generics need not be true of all category members, unlike universal quantifiers (e.g., every, each). This article examined whether preschool children and adults appreciate both these features, using a comprehension task (Study 1) and an elicited production task (Study 2). In both tasks, 4-year-old children--like adults--treated generics as distinct from both indefinites (some) and universal quantifiers (all). In contrast, 3-year-olds did not differentiate among generics, all, and some. By 4 years of age, generics emerge as a distinct semantic device.