Adults\' face processing may be specialized for the dimensions of young adult faces. For example, young and older adults exhibit increased accuracy in normality judgments and greater agreement in attractiveness ratings for young versus older adult faces. The present study was designed to examine whether there is a similar young adult face bias in facial age estimates. In Experiment 1, we created a face age continuum by morphing an averaged young adult face with an averaged older adult face in 5% increments, for a total of 21 faces ranging from 0 to 100% old. Young and older adults estimated facial age for three stimulus age categories [young (morphs 0-30%), middle-aged (morphs 35-65%), and older adult (morphs 70-100%)]. Both age groups showed the least differentiation in age estimates for young adult faces, despite showing greater consensus across participants in estimates for young faces. In Experiment 2, young and older adults made age estimates for individual young and older adult identities. Both age groups were more accurate and showed greater consensus in age estimates for young faces. Collectively, these results provide evidence for a bias in processing young adult faces beyond that which is often observed in recognition and normality/attractiveness judgment tasks.

Adults are more accurate in detecting deviations from normality in young adult faces than in older adult faces despite exhibiting comparable accuracy in discriminating both face ages. This deficit in judging the normality of older faces may be due to reliance on a face space optimized for the dimensions of young adult faces, perhaps because of early and continuous experience with young adult faces. Here we examined the emergence of this young adult face bias by testing 3- and 7-year-old children on a child-friendly version of the task used to test adults. In an attractiveness judgment task, children viewed young and older adult face pairs; each pair consisted of an unaltered face and a distorted face of the same identity. Children pointed to the prettiest face, which served as a measure of their sensitivity to the dimensions on which faces vary relative to a norm. To examine whether biases in the attractiveness task were specific to deficits in referencing a norm or extended to impaired discrimination, we tested children on a simultaneous match-to-sample task with the same stimuli. Both age groups were more accurate in judging the attractiveness of young faces relative to older faces; however, unlike adults, the young adult face bias extended to the match-to-sample task. These results suggest that by 3 years of age, children\'s perceptual system is more finely tuned for young adult faces than for older adult faces, which may support past findings of superior recognition for young adult faces.