Explaining the disambiguation effect: don't exclude mutual exclusivity.

When they see a familiar object and an unfamiliar one, and are asked to select the referent of a novel label, children usually choose the unfamiliar object. We asked whether this 'disambiguation effect' reflects an expectation that each object has just one label (mutual exclusivity), or an expectation about the intent of the speaker who uses a novel label. In Study 1, when a speaker gazed at or pointed toward the familiar object in a novel-familiar pair, children aged 2 ; 6 (N=64) selected that object in response to a neutral request, but were much less likely to do so in response to a label request. In Study 2, when a speaker both gazed at and pointed toward the familiar object, toddlers (N=16) overwhelmingly selected the familiar object in response to a label request. The expectation that each object has just one label can lead children to discount some individual behavioral cues to a speaker's intent, though it can be overridden given a combination of pragmatic cues.