Seeing pink elephants: fourteen-month-olds' interpretations of novel nouns and adjectives.

Words from different grammatical categories (e.g., nouns and adjectives) highlight different aspects of the same objects (e.g., object categories and object properties). Two experiments examine the acquisition of this phenomenon in 14-month-olds, asking whether infants can construe the very same set of objects (e.g., four purple animals) either as members of an object category (e.g., animals) or as embodying a salient object property (e.g., four purple things) and whether naming (with either count nouns or adjectives) influences infants' construals. Results suggest (1) that infants have begun to distinguish count nouns from adjectives, (2) that infants share with mature language-users an expectation that different grammatical forms highlight different aspects, and (3) that infants recruit these expectations when extending novel words. Further, these results suggest that an expectation linking count nouns to object categories emerges early in acquisition and supports the emergence of other word-to-world mappings.