Increasing Perceived Outgroup Heterogeneity Following Exposure to Extreme Violence: An Intervention Tournament in Times of War.

Exposure to political violence often drives individuals toward extreme attitudes and greater support for retaliatory policies, including heightened perceptions of outgroup homogeneity. In violent intergroup conflicts, such perceptions can be especially dangerous, as they may justify indiscriminate violence against the outgroup. The current research aims to address Jewish Israelis' perceptions of Palestinians' variability following the October 7 Hamas attack on Israel. We simultaneously conducted two intervention tournaments in which we examined the effectiveness of different interventions in increasing the perceived heterogeneity of Palestinians from the West Bank and Gaza Strip (N = 1,564) and of Palestinian citizens of Israel (N = 1,628). Several interventions (Outgroup empathy expression, Opinion variance, Internal criticism, Leadership-people distinction, and Moral exemplars) were found effective, suggesting that outgroup perceptions can be altered, even amid extreme violence. Implications for psychological interventions targeting outgroup variability and their implementation in the field are discussed.