Altruism and Prosocial Behavior

The psychological study of prosocial behavior covers a wide range of actions that people perform to benefit other persons or groups. Although instances of interpersonal (i.e., one-to-one) helping, in which one person provides assistance to another, have dominated investigations into prosocial behavior for many years, theory and research has since broadened from this initial focus to consider collective forms of prosocial behavior (e.g., volunteerism and participation in social movements) and the dynamics of cooperation within and between collectives. Investigators have sought to understand what leads people to engage in these behaviors, identifying sources of prosocial motivation that are internal (such as personal needs and drives) and external (such as situational demands and social norms). We review theory and research seeking to understand diverse sources of prosocial motivation across three distinct categories of prosocial behavior: interpersonal prosocial behavior, collective prosocial behavior, and cooperation within and between collectives.