The Impact of Social Ties on Group Interactions: Evidence from Minimal Groups and Randomly Assigned Real Groups

Teams, departments, communities, etc., are very prevalent in organizations and society. Membership in those groups may affect the willingness of members to engage in prosocial behaviors like altruistic cooperation, or norm enforcement, which enhance efficiency but involve no personal material reward (e.g., Akerlof and Kranton 2000, 2005). Group boundaries might impact prosocial behavior through two psychological channels: by creating a “label” that can cause someone to “identify” with the group; and by affecting the circle of people an individual interacts with, leading to formation of social ties with fellow group members. A large body of evidence from “minimal group” experiments in psychology (e.g., Tajfel et al. 1971) sheds light on the first of these effects, showing that “even the most minimal group assignment can affect behavior” (Akerlof and Kranton 2000, 720). That is, even a “minimal group,” which in its purest form is nothing more than an arbitrary label, can increase subjects’ willingness to help individuals with the same label, as opposed to subjects with a different label. This finding inspired social identity theory (e.g., Tajfel and Turner 1979), which assumes that individuals “identify” with even arbitrary group labels, and favor those with the same label.