Reciprocity in Interpersonal Relationships: An Evolutionary Perspective on Its Importance for Health and Well-being

Abstract
Based on an evolutionary analysis of reciprocal altruism, it is argued that humans have developed innate mechanisms to expect reciprocity in interpersonal relationships and that a lack of reciprocity is accompanied by negative affect. The authors present an overview of their own research programme documenting the importance of reciprocity in a wide variety of relationships, including marital relationships, lesbian relationships, extradyadic sexual relationships, friendships, professional and informal helping relationships, relationships with colleagues and supervisors at work, and relationships with the organization in which one is employed. In view of this broad range of relationships that seem to be governed by similar principles of reciprocity, it seems that a basic psychological mechanism is at work, and we suggest that this is rooted in evolution.