The theme of cooperation has been a prominent domain of theory and research within a variety of disciplines, including philosophy, political science, economics, sociology, biology, and psychology. The broad interest in cooperation is not surprising. This theme is intimately linked to the basic views and assumptions regarding human nature and relevant to the functioning of dyads, groups or organizations, and even societies. Although it is often assumed that humankind is rationally selfinterested, more recent theorizing and research reveals that human nature is far richer than the concept of selfishness is able to capture.