The evolution of cooperation among nonrelatives has been explained by direct, indirect, and strong reciprocity. Animals should base the decision to help others on expected future help, which they may judge from past behavior of their partner. Although many examples of cooperative behavior exist in nature where reciprocity may be involved, experimental evidence for strategies predicted by direct...

Time-consuming and costly religious rituals pose a puzzle for economists committed to rational choice theories of human behavior. We propose that religious rituals promote in-group trust and cooperation that help to overcome collective-action problems. To test this hypothesis we design field experiments to measure the in-group cooperative behavior of members of religious and secular Israeli kib...

Cooperation applies the situations where two or more individuals obtain a net benefit by working together. Cooperation is widely spread in nature and takes several forms, ranging from behavioral coordination to sacrifice of one’s own life for the benefit of the group. This latter form of cooperation is known as “true cooperation”, or “altruism”, and is found only in few cases. Truly cooperative...

We have formalized a finite iterated game with change. The formalization extends a traditional framework, e.g., prisoner’s dilemma, by incorporating an influence on the payoff matrix at some future point through the execution of an action at the present time. This enables us to explain why cooperative behavior emerges in human interactions, even though from a myopic view, cooperative behavior d...