Abstract # 13200 Event # 120:

Scheduled for Friday, August 10, 2018 10:30 AM-10:45 AM: (Chula Vista ) Oral Presentation


THE ROLE OF OXYTOCIN IN AFFILIATIVE SOCIAL BEHAVIOR IN TUFTED CAPUCHIN MONKEYS (CEBUS [SAPAJUS] APELLA)

M. J. Sosnowski1,2, M. E. Benítez1,2, O. B. Tomeo1,2 and S. F. Brosnan1,2,3
1Department of Psychology, Georgia State University, Atlanta, GA 30302, USA, 2Language Research Center, Georgia State University, 3Neuroscience Institute, Georgia State University
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     Oxytocin has been identified as a key player in sociality, including in social bond formation and maintenance. Despite ongoing interest in the relationship between oxytocin and sociality, our understanding of oxytocin’s role in primate social behavior, especially in non-monogamous New World monkeys, is limited. We investigated the relationship between oxytocin and two naturally-occurring affiliative behaviors, grooming and fur-rubbing, in 18 socially-housed tufted capuchin monkeys (Cebus [Sapajus] apella). Capuchins are a gregarious, cooperative species and thus ideal for studying hormones in primate social behavior. First, we successfully validated a method for analyzing urinary oxytocin in capuchins (Linearity: t(8)=0.68, p=0.52, Extraction Recovery: t(6)=0.34, p=0.75). We found that exogenous oxytocin administration significantly increased urinary oxytocin for 15-60 minutes post-administration, with the largest effect between 30-45 minutes (LMM; beta=0.76, t=5.22, p<0.001). Second, we found that urinary oxytocin was significantly related to grooming and fur-rubbing. Specifically, urinary oxytocin increased after individuals received grooming (beta=0.28, t=2.10, p=0.038) or participated in a fur-rubbing bout (beta=0.27, t=2.07, p=0.04). Interestingly, we found an increase in affiliative behaviors during and immediately after a fur-rubbing bout; however, 15-30 minutes post-bout, these behaviors decreased (beta=-0.85, z=-3.62, p<0.001), supporting prior evidence that oxytocin may counterintuitively increase social distance in this species. Taken together, our results provide further evidence for an important yet complex role of oxytocin in affiliative bond formation in primates.