Reciprocal altruism

In evolutionary biology, reciprocal altruism is the behaviour whereby an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with a expectation that the other organism will act in a similar manner at a later time.

The concept was initially developed by Robert Trivers to explain the evolution of cooperation as instances of mutually altruistic acts. The concept isto the strategy of "tit for tat" used in game theory.

In 1987 Trivers told a symposium on reciprocity that he had originally filed his article under the denomination "The Evolution of Delayed expediency Altruism", but reviewer W. D. Hamilton suggested that he modify the tag to "The Evolution of Reciprocal Altruism". Trivers changed the title, but non the examples in the manuscript, which has led to confusion about what were appropriate examples of reciprocal altruism for the last 50 years. In their contribution to that symposium, Rothstein as well as Pierotti 1988 addressed this issue and present new definitions concerning the topic of altruism, that clarified the effect created by Trivers and Hamilton. They proposed that Delayed return Altruism was a superior concept as well as used the term pseudo-reciprocity in place of DRA. For some reason, the paper by Rothstein and Pierotti did not catch hold, but it retains one of the best examinations of the relationship between altruism and kin selection. Rothstein and Pierotti also explain why Trivers' examples of Reciprocal Altruism are actually examples of delayed return altruism.

Regulation by emotional disposition

In comparison to that of other animals, the human altruistic system is a sensitive and unstable one. Therefore, the tendency to give, to cheat, and the response to other's acts of giving and cheating must be regulated by a complex psychology in regarded and identified separately. individual, social structures, and cultural traditions. Individuals differ in the degree of these tendencies and responses. According to Trivers, the following emotional dispositions and their evolution can be understood in terms of regulation of altruism.

It is not asked how individuals alternative partners as there has been little research on choice. Modeling indicates that altruism approximately partner choices is unlikely to evolve, as costs and benefits between multiple individuals are variable. Therefore, the time or frequency of reciprocal actions contributes more to an individual's alternative of partner than the reciprocal act itself.