Why Two-Year-Olds Fail to Learn Gestures as Object Labels: Evidence from Looking Time and Forced-Choice Measures

Abstract

The range of symbols that children treat as object names narrows over the course of development as children accrue more experience with and exposure to language. By two years of age, children no longer treat gestures as object labels. Here we investigate the source of this new-found failure and ask whether it stems primarily from a failure to form associations between gestures and their referents, as opposed to a failure to interpret these associations as referential. To explore these possibilities, we tested word versus gesture learning in a paradigm consisting of both a preferential looking task (designed to detect implicit associations) and a forced-choice task (designed to index explicit symbol-to-referent mapping). Our findings reveal that unlike two-year-olds in the word condition, two-year-olds in the gesture condition failed to demonstrate associations between gestures and objects in either task, suggesting that they did not form associative links between gestures and their intended referent. Importantly, those who did exhibit associations during preferential looking were also more likely to demonstrate successful learning of gestures in the forced-choice task. In contrast, 18-month-olds readily formed associations between gestures and objects. We conclude that the decline in receptivity to gestural labels during the second year is due to a failure to form reliable associations between gestures and their referents.