Fifteen minute-old neonates show no preference for attractive faces over unattractive faces. But 72 hours later they already stare longer at faces judged by adults to be attractive than they do at unattractive faces. This rapid development of an appreciation of facial beauty (as judged by adults) might be explained by the fact that an averaged face made of 32 faces looks almost indistinguishable from any other 32-face averaged face even when they are created from a completely different set of individuals. It is thus possible that an average of only 32 facial exemplars is sufficient to approximate the population mean, and thus produce a prototype that is shared by almost everyone in a community. Kalakanis estimated that newborns see between 5 and 10 faces before they leave hospital in the USA. Thus, after 72 hours, they will have abstracted a prototypical face that is very close to the community's norm. Faces are an important class of visual stimuli for humans, and the perception of "faceness" is a critical part of social responsiveness. Because of the importance of the information conveyed by faces for social interaction, humans should therefore have innate preferences for them as a category, with its associated prototype.