Abstract # 140:

Scheduled for Sunday, September 14, 2014 04:30 PM-04:45 PM: Session 21 (Mary Gay) Oral Presentation


C. F. Talbot1,2,3, K. Hall3, L. E. Williams3 and S. F. Brosnan1,2,3,4
1Georgia State University, Department of Psychology, Atlanta, GA, USA, 2Language Research Center, Georgia State University, Atlanta, GA USA, 3Department of Veterinary Services, Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas M.D. Anderson Cancer Center, Bastrop, TX USA, 4Neuroscience Institute, Georgia State University, Atlanta, GA USA

Negative responses to inequity are proposed to have evolved in tandem with cooperation as a means to compare one’s own and others’ outcomes. According with this hypothesis, several species of cooperative primates react negatively to receiving less than a partner. Squirrel monkeys, who are not known to cooperate in the wild, do not respond to inequity, yet no study has directly examined cooperation in this species. Here, we tested unrelated squirrel monkeys (Saimiri spp.) on a cooperative bar pull task modeled on one used with capuchin monkeys. Data thus far show that squirrel monkeys do coordinate on the task, and their responses differed depending on the value and distribution of the rewards (Q(2)=144.06, p< 0.001). Subjects were more likely to coordinate their actions in the presence of a high value reward regardless of equitability (e.g., Unequal vs. Mutual Low conditions; p<0.001), but this appeared to be tempered by the opportunity for reward monopolization. Subjects were less likely to coordinate when rewards were clumped as opposed to dispersed (Clumped High vs. Mutual High, p<0.001). Thus, although squirrel monkeys were primarily motivated by the absolute value of the rewards, they were still sensitive to subsequent competition, which had a negative effect on coordination. Next we plan to pair this task with a traditional inequity test to examine whether subjects’ willingness to coordinate correlates with their responses to inequity.