Abstract
This chapter examines evidence for phylogenetic origins that is revealed in continuities between face perception in nonhuman animals and human infants and the first impressions shown by human adults. It provides four kinds of evidence pertinent to the evolutionary origins of impression formation. First, it shows a phylogenetic foundation for overgeneralization effects in a shared sensitivity across species to particular facial qualities and their affordances. Second, it shows similar sensitivities in human infants. Third, it provides direct evidence that overgeneralized reactions to these facial qualities contribute to first impressions. Finally, the chapter provides neural data concerning the arguments presented. This is done for facial qualities that convey familiarity, neoteny, emotion, fitness, and species.