Testing for anticipation of partners' reciprocity and other social parameters: An experimental approach in wild vervet monkeys (Chlorocebus pygerythrus).

It has been suggested that social challenges in group-living species in which individuals maintain long-term relationships select for advanced cognitive processes. A key challenge for testing this hypothesis is to design experiments that allow the assessment of animals' knowledge of conspecifics and how they use that information to their own advantage. Here, we present data on wild vervets using an experimental paradigm that induced a competitive context. After training females to obtain food from a personal box, we placed their box in proximity to another monkey's personal box to create potential conflict. We have previously shown that high-ranking female vervets exchange tolerance, though to a lesser extent when the audience contains an individual that outranks the subordinate partner, and coalitionary support for grooming. Our questions here were (a) whether subordinates adjust the likelihood of approaching their box when their recent dominant grooming partners are already present and (b) if dominants are more likely to threaten the box partner in the presence of their recent high-ranking grooming partner. Although we found some effects of age and group on the subjects' behavior, no evidence emerged that subordinates incorporate the effects of recent grooming history. Dominants were more likely to threaten the box partner in the presence of a high-ranking individual within the audience, independent of their own grooming history. We suggest that our paradigm can be used to discern the degree to which individuals of different species take into account recent social history with others that affect these others' behavior toward themselves. (PsycINFO Database Record (c) 2018 APA, all rights reserved).