Preschoolers' use of form class cues to learn descriptive proper names.

This study examined 3- and 4-year-old preschoolers' ability to learn proper names containing familiar descriptions. Children saw a novel creature with a familiar property (it was red) and heard either an adjective ("This is a red one") or a descriptive proper name ("This is Mr. Red"). The creature was then transformed, losing the property (e.g., it became green). Children had to extend the word to either the transformed original creature or a new creature bearing the original property (another red creature). Children, especially 4-year-olds, extended the adjective to the new creature but were significantly more likely to extend the proper name to the original creature. Lexical form class cues provided potent information about word meaning, directing preschoolers to reinterpret familiar descriptive terms (adjectives) as homophonic terms designating unique individuals (proper names).