The influence of rank on affect perception by pigtailed macaques (Macaca nemestrina)

Previous studies of affect perception in nonhuman primates have involved young animals and/or manipulations of early experience. Based upon data suggesting that middle-ranked monkeys in small social groups show patterns of behavior different from their low- or high-ranked counterparts, the current study examined the role of social rank in affect perception by normally reared, adult female pigtailed macaques. Employing color videotapes as the presentation medium, we observed animals as they watched unfamiliar animals display social (aggressive or submissive) or nonsocial behavior. Virtually all threats were recorded as the subjects watched the submissive presentations, and most submissive signals occurred while watching aggressive behavior tapes. Middle-ranked monkeys were most attentive during all presentations, and levels of disturbance behavior were related to rank of the watcher and type of presentation observed. The results suggest that dominance status is an influence in the process of affect perception.