Observations on development of person constancy

Despite recent research into the development of several perceptual constancies in infants and young children (1, 2 ) , few data are available on the development of person constancy. By person constancy we mean identification of a stimulus source ( a person) as the same despite changes or differences in general appearance due to age, dress, grooming, facial expression, context, etc. (5, pp. 330-348). The development of person consrancy probably involves discrimination of progressively higher-order invariant properties of stimulation, and increasing tolerance of variation in total stimulus input (3, pp. 347356; 450-472). A major set of stimuli enabling person constancy is afforded by the face. Gibson ( 3 ) has reviewed a large body of evidence regarding infants' and children's responses to faces and face-like displays. She has specifically proposed that the child comes to extract critical features of an oft-presented face, later picks up invariant relations among such feattires, and still later responds to a ". . . unique feature pattern characterizing a particular face. . . ." This Last process is referred to here as person constancy. There is some degree of person constancy allowing recognition of familiar faces despite minor changes in orientation, projected size, etc., by the time a child is 8 mo. old ( 3 ) . But little evidence bears on the progressive ability of a child to recognize even a highly familiar face as the same, with extreme or discontinuous changes in total stimulus input which might prevent the utilization of those invariants allowi.ng a face to be so recognized. In that little formally gathered evidence bears on questions of when constancy shifts to higher-order stimuli may occur, the following observations seem worth reporting. Observations were of the author's son' between 7 and 18 mo. of age. For the first 7 mo. of the child's life, his father wore a beard and mustache. From about 4 to 7 mo., presenting the father's bearded face to the child at a distance of about 1 ft. elicited smiling, vocalization, and later, reaching, touching, grasping, and pulling of the beard. At about G mo. of age, if the child's mother said: "Where's daddy?" when the child was not looking at the father, the child began visual search of the room which terminated when the father was fixated. Search did not terminate on two other bearded men visiting the home, implying that stimulus features ocher than a beard pe? se were being used to distinguish the father from others. When the child was 7 mo. old, the father's beard and mustache were shaved. Presentation of this version of the face in the usual position and context failed to produce the various recognition behaviors noted above. Visual search to "Where's daddy?" no longer terminated when the father was fixated. Several weeks of repeated presentation were required before recognition indices reappeared. These observations suggest that complete person constancy-even for a highly salient person-was not present at 7 mo., but that the child recognized his father via some beard/mustache-related critical features specific to the father's beard/mustache. This stage of recognition has been noted by Gibson ( 3 ) . Beard and mustache were regrown when the child was 9 to 10 mo. old. During this period the child labeled the father "daddy." At 15 mo. the child spontaneously labeled