Reciprocal Altruism

Rooted in evolutionary biology and multi-iteration game theory, reciprocal altruism is a cooperative strategy in which someone chooses to perform an act that incurs an immediate net personal cost to benefit another individual in the hope of reaping a future gain. In biological terms, it represents a willingness to forego one's own reproductive chances in favor of another's chances for the overall benefit of the group. This goes beyond a form of altruism dictated by kin selection in that the short-term selfless behavior is extended to organisms that do not necessarily share a common ancestry. In an evolutionary sense, it seems as though a behavior that imposes a greater net cost on one individual for the sake of an unrelated person would be selected out. ...