It takes one to know one: Do human and nonhuman primates share similar face processing?

International audienceThe ability to identify individuals within the group, and to interpret their expressions and intentions is essential for many social animals. Face recognition in human and non human primate stems from a conjunction of evolutionary inheritance and experience via exposure to faces present in the environment. Individuation is clearly a vital mechanism for any social species. By uncovering similarities across primate face systems, comparative studies allow us to understand the evolution of face processing capabilities in humans. Some researchers have argued that primates, including humans, may possess an innate face processing system that is predisposed to respond to conspecifics. The argument is supported by a study showing that monkeys raised without experience of other own-species monkeys will still prefer to look at faces of conspecifics (Fujita, 1990). However, this proposal does not fit well with findings from the human infant literature (Pascalis et al., 2002) or with new data on monkeys raised without seeing faces (Sugita, 2008) which both suggest that face processing is highly shaped by experience at an early age. We will argue that humans and nonhuman primates possess an evolved system for processing faces that become specialized as a consequence of predominant exposure to faces from a single species. According to this interpretation, a limitation of the face processing expertise to own species should be observed