Nature may be red in tooth and claw, but working together with one’s group mates can be an efficient way to increase fitness. Cooperation is common, for example, among capuchin monkeys. These monkeys are not only willing to help others obtain resources, but are more likely to share with individuals who help them. Cooperation can be risky, however, and not surprisingly capuchins are much less likely to cooperate when a partner is able to monopolize the reward. However, they also pay attention to the partner’s behavior; monkeys who share with their partners promote successful cooperation, and thus actually receive more benefits over the long term than those who always claim the best rewards for themselves. The ability to recognize inequity may be a mechanism by which the monkeys determine which partners are the best collaborators. The study of capuchin monkeys can tell us quite a lot about how, when, and with whom to cooperate, perhaps providing insight in to the design and implementation of our own human cooperative institutions
