Abstract
Mass gatherings are routinely viewed as posing risks to physical health. However, social psychological research shows mass gathering participation can also bring benefits to psychological well‐being. We describe how both sets of outcomes can be understood as arising from the distinctive forms of behavior that may be found when people—even strangers—come to define themselves and each other in terms of a shared social identity. We show that many of the risks and benefits of participation are products of group processes; that these different outcomes can have their roots in the same core processes; and that knowledge of these process provides a basis for health promotion interventions to mitigate the risks and maximize the benefits of participation. Throughout, we offer practical guidance as to how policy makers and practitioners should tailor such interventions.