Known and novel noun extensions: attention at two levels of abstraction.

Two experiments tested the hypothesis that names direct attention at two levels of abstraction: Known names direct attention to the properties most relevant to the specific category; novel names direct attention to the shape, the property most generally relevant across known object names. English-speaking and Japanese-speaking 3-year-olds were shown a novel object that was named with (a) known nouns referring to things similar in shape or similar in material and color, and (b) novel nouns. Given known nouns, children attended to shape when the name referred to a category organized by shape, but they did not when the name referred to a category organized by other properties. Children generalized novel names by shape. The results are discussed within the debate between shape-based and taxonomic categories.