In social psychology, reciprocity refers to in-kind positive or negative responses of individuals towards the actions of others. Thus positively interpreted actions elicit positive responses and vice versa. Positive reciprocal actions differ from altruistic actions as they only follow from other positive actions and they differ from social gift giving in that they are not actions taken with the hope or expectation of future positive responses. Social psychology is the study of the nature and causes of human social behavior, with an emphasis on how people think towards each other and how they relate to each other. ... Altruism refers to both a practice or habit (in the view of many, a virtue) as well as an ethical doctrine. ... This page is about the computer software giFT. For other uses, see gift (disambiguation) giFT stands for giFT: Internet File Transfer. ...

Reciprocal actions are important to social psychology as they can help explain the maintenance of social norms. If a sufficient proportion of the population interprets the breaking a social norm by another as a hostile action and if these people are willing to take (potentially costly) action to punish the rule-breaker then this can maintain the norm in the absence of formal sanctions. The punishing action may range from negative words to complete social ostracism. In sociology, a norm, or social norm, is a pattern of behavior expected within a particular society in a given situation. ... In modern parlance, to ostracize means to exclude someone from society or from a community, by not communicating with or even noticing them, similar to shunning. ...

In public good experiments, behavioral economists have demonstrated that the potential for reciprocal actions by players increases the rate of contribution to the public good, providing evidence for the importance of reciprocity in social situations (Fehr and Gatcher, 2003). In economics, a public good is a good that is hard or even impossible to produce for private profit, because the market fails to account for its large beneficial externalities. ...

In mathematics, game theory describes reciprocity as a highly effective Tit for Tat strategy for the iterated prisoner's dilemma. Hi dustin ... Game theory is a branch of applied mathematics that uses models to study interactions with formalised incentive structures (games). Unlike decision theory, which also studies formalised incentive structures, game theory encompasses decisions that are made in an environment where various players interact strategically. ... Tit for Tat is a highly-effective strategy in game theory for the iterated prisoners dilemma. ... Will the two prisoners cooperate to minimise total loss of liberty or will one of them, trusting the other to cooperate, betray him so as to go free? The prisoners dilemma is a type of non-zero-sum game. ...

References

Fehr, E.; Simon Gächter, Ss, 'Fairness and Retaliation: The Economics of Reciprocity' in Camerer, C.; Lowenstein, G.; Rabin, M. (eds.) Advances in Behavioral Economics (2003)