Infant sensitivity to deviations in dynamic facial-vocal displays: the role of eye regard.

Do young infants appreciate the intentionality of adult interactors? In view of recent speculation that infants are innately sensitive to eye direction and that communicative intent is conveyed in part by attentional cues, the reactions of 3- and 5-month infants were compared to video episodes of normally responsive women who either appeared or did not appear to make eye contact. Across three experiments, lack of eye contact was achieved by either averting the eyes (E), averting the head and eyes (H&E), closing the eyes (ECL), or averting the head alone (H). Three-month-olds smiled less at H&E, H, and ECL, but not at E, relative to frontal faces, indicating sensitivity to head but not to eye orientation. By contrast, 5-month-olds smiled less at H&E, E, and ECL, but not at H, indicating sensitivity to both head and eye orientation. The implications of the data for mentalist views of infant social behavior are discussed.