Goal certainty modulates infants' goal-directed gaze shifts

We investigated whether 12-month-old infants rely on information about the certainty of goal selection in order to predict observed reaching actions. Infants' goal-directed gaze shifts were recorded as they observed action sequences in a multiple-goals design. We found that 12-month-old infants exhibited gaze shifts significantly earlier when the observed hand reached for the same goal object in all trials (frequent condition) compared with when the observed hand reached for different goal objects across trials (nonfrequent condition). Infants in the frequent condition were significantly more accurate at predicting the action goal than infants in the nonfrequent condition. In addition, findings revealed rapid learning in the case of certainty and no learning in the case of uncertainty of goal selection over the course of trials. Together, our data indicate that by the end of their first year of life, infants rely on information about the certainty of goal selection to make inferences about others' action goals.