When it is apt to adapt: Flexible reasoning guides children's use of talker identity and disfluency cues.

An eye-tracking methodology was used to examine whether children flexibly engage two voice-based cues, talker identity and disfluency, during language processing. Across two experiments, 5-year-olds (N = 58) were introduced to two characters with distinct color preferences. These characters then used fluent or disfluent instructions to refer to an object in a display containing items bearing either talker-preferred or talker-dispreferred colors. As the utterance began to unfold, the 5-year-olds anticipated that talkers would refer to talker-preferred objects. When children then encountered a disfluency in the unfolding description, they reduced their expectation that a talker was about to refer to a preferred object. The talker preference-related predictions, but not the disfluency-related predictions, were attenuated during the second half of the experiment as evidence accrued that talkers referred to dispreferred objects with equal frequency. In Experiment 2, the equivocal nature of talkers' referencing was made more apparent by removing neutral filler trials, where objects' colors were not associated with talker preferences. In this case, children ceased making all talker-related predictions during the latter half of the experiment. Taken together, the results provide insights into children's use of talker-specific cues and demonstrate that flexible and adaptive forms of reasoning account for the ways in which children draw on paralinguistic information during real-time processing.