Five- and eight-month-old infants recognize their faces and voices as familiar and social stimuli.

Five- and 8-month-old infants were presented with silent moving and static video images of self, peer, and doll and with sounds of self, peer, and nonsocial objects. In the visual conditions, infants at both ages showed a significant looking preference to peer over self when the faces were moving. When the faces were static, older infants showed the same significant discriminations, but the younger infants showed a significant looking preference for their own faces over peer and doll. These data suggest that recognition of one's own image develops through experience with dynamic facial stimulation during the first 8 months of life. In the auditory conditions, infants at both ages showed significant looking preferences for sounds of peer over self or nonsocial objects. In general, infants of both ages smiled and produced more vocalizations to social faces and social sounds than to nonsocial faces and nonsocial sounds. Thus, at 5 months infants treat their faces and voices as familiar and social stimuli. The findings forge important links among studies of self-perception, self-recognition, and social knowledge.