Abstract
Peer competition and peer cooperation can be intuitively seen as opposing phenomena. However, depending on multiple factors, they might be complementary. In a population divided into groups, for instance, members of each group may cooperate with their peers in order to compete with neighboring groups. Alternatively, they may compete with their peers as a means of choosing the best cooperative partners and demonstrate that they are reliable cooperative partners. For instance, if subjects can choose with whom they wish to interact, this may create competition to be more generous or loyal than others.