Category markers or attributes: why do labels guide infants' inductive inferences?

To clarify the role of labels in early induction, we compared 16-month-old infants' (n=114) generalization of target properties to test objects when objects were introduced by the experimenter in one of the following ways: (a) with a general attentional phrase, (b) highlighted with a flashlight and a general attentional phrase, (c) via a recorded voice that labeled the objects using a naming phrase, (d) with a label consisting of a count noun embedded within a naming phrase, (e) with a label consisting of a single word that was not marked as belonging to a particular grammatical form class, and (f) with a label consisting of an adjective. Infants relied on object labels to guide their inductive inferences only when the labels were presented referentially, embedded within an intentional naming phrase, and marked as count nouns. These results suggest that infants do not view labels as attributes of objects; rather, infants understand that count-noun labels are intentional markers denoting category membership.