Recognition of individual faces and average face prototypes by 1- and 3-month-old infants

We tested the ability of 1- and 3-month-old infants to form prototypic representations of faces. Following familiarization to four individual faces, both 1- and 3-month-olds showed evidence of recognizing the individual faces but only 3-month-olds showed evidence of recognizing, and thus having mentally computed, the average of the four face stimuli. Additional experiments showed that (a) 1-month-olds failed to show evidence of recognizing the average face even when the test was made easier, and (b) the results could not be attributed to preexisting visual preferences among the faces. These results are discussed in relation to a two-process theory of the development of face recognition and the hypothesis that babies' abilities to form prototypes of faces underlies their visual responsiveness to attractive faces.