In social psychology, reciprocity is a social norm of responding to an action executed by another person with a similar or equivalent action. This typically results in rewarding positive actions and punishing negative ones. As a social construct, reciprocity means that in response to friendly actions, people are generally nicer and more cooperative. This construct is reinforced in society by fostering an expectation of mutual exchange. While the norm is not an innate quality in human beings, it is learned and cemented through repeated social interaction. Reciprocity may appear to contradict the predicted principles of self-interest. However, its prevalence in society allows it to play a key role in the decision-making process of self-interested and other-interested (or altruistic) individuals. This phenomenon is sometimes referred to as reciprocity bias, or the preference to reciprocate social actions.
Reciprocal actions differ from altruistic actions in that reciprocal actions tend to follow from others' initial actions, or occur in anticipation of a reciprocal action, while altruism, an interest in the welfare of others over that of oneself, points to the unconditional act of social gift-giving without any hope or expectation of future positive responses. Some distinguish between pure altruism (giving with no expectation of future reward) and reciprocal altruism (giving with limited expectation or the potential for expectation of future reward). For more information on this idea, see altruism or altruism (ethics).
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