Abstract # 115:

Scheduled for Saturday, August 26, 2017 03:30 PM-03:45 PM: (National Ballroom Salon A) Oral Presentation


C. F. Talbot1,2,3 and S. F. Brosnan1,2,4
1Department of Psychology, Georgia State University, Atlanta, GA 30302, USA, 2Language Research Center, Georgia State University, Atlanta, GA, USA, 3California National Primate Research Center, University of California, Davis, CA, USA, 4Department of Philosophy, Neuroscience Institute, Georgia State University, Atlanta, GA, USA

Several species of nonhuman primates (NHPs) extract information about individual identity from faces alone, however little is known about whether NHPs extract other social information, such as the sex of the conspecific, which is fundamental to their reproductive success. Although previous research in the visual domain is limited, it suggests that conspicuous sexual features, in addition to faces, may play an important role in sex categorization. Yet unlike the species previously tested on sex discrimination tasks (e.g., macaques and chimpanzees), many New World species, including capuchin monkeys, do not show conspicuous sexual features. Capuchins nonetheless display dimorphism in facial morphology suggesting that they may deduce the sex of an individual from facial morphology alone. Using a computerized dichotomous choice task, I tested whether capuchin monkeys (n=14) categorized the sex of conspecifics from faces alone and whether familiarity aided performance. Overall, the capuchins did not perform above chance on the sex discrimination task and no effect of familiarity was observed (ANOVA: F2,24 = 0.435, p = 0.562). However, the four subjects that did not exhibit a side bias chose “male” significantly more often when a male photo was presented than when a female photo was presented. (McNemar Test: χ2 = 36.029, p < 0.0001). Although some capuchins may have learned the task, it seems likely that capuchins discriminate sex through alternative, or multiple, modes of communication.