Experience-dependent changes in the development of face preferences in infant rhesus monkeys

It is well known that early experience shapes the development of visual perception for faces in humans. However, the effect of experience on the development of social attention in non-human primates is unknown. In two studies, we examined the effect of cumulative social experience on developmental changes in attention to the faces of unfamiliar conspecifics or heterospecifics, and mom versus an unfamiliar female. From birth, infant rhesus monkeys preferred to look at conspecific compared to heterospecific faces, but this pattern reversed over time. In contrast, no consistent differences were found for attention to mom's face compared to an unfamiliar female. These results suggest differential roles of social experience in shaping the development of face preferences in infant monkeys. Results have important implications for establishing normative trajectories for the development of face preferences in an animal model of human social behavior.