Reciprocity (Social Psychology)

In social psychology, reciprocity is a social norm of responding to an action taken by another person with a similar or equivalent action, typically rewarding positive actions and punishing negative ones, so that in response to friendly behavior people tend to become nicer and more cooperative in turn. It is not an innate quality but one learned and reinforced through repeated social interaction, and although it may appear to contradict pure self-interest, its prevalence in society gives it a real role in the decision-making of both self-interested and altruistic individuals, a tendency sometimes called reciprocity bias. It differs from altruism, an unconditional interest in another's welfare given without hope of a return, in that a reciprocal action follows from or anticipates another person's own action.