Abstract
Consideration of social cognition—how an individual’s decision-making is influenced by her/his social environment—is key to understanding the behaviour of socially living nonhuman primates. In this chapter we discuss primate social cognition by focusing on primates’ behavioural responses to the presence and actions of others, how they adjust their behaviour to maximize their own gains, and possibly also the rewards received by a partner. Individuals can observe and replicate the actions of others, or the outcomes of their actions, to accelerate behavioural acquisition of techniques to obtain rewards. Beyond passively observing others, primates can also work with group mates to obtain rewards more easily or to get rewards that would otherwise be unattainable by a single individual. Although not universally seen among primates, one individual may also help another to acquire resources. Prosocial and collaborative interactions may result in an imbalance of benefits received, and certain primate species respond negatively when receiving less than a social partner, a response which may protect individuals against cheating. Such behaviours demonstrate how the interplay between an individual’s desires and those of others can modify behavioural outcomes and the importance of considering cognition from a social perspective in order to understand the decision-making of individuals. However, there is variation both within and between species in their sensitivity to the actions of others and their responses to them. Thus, a comparative framework is needed when studying what is meant by ‘primate social cognition’.