A collective blame hypocrisy intervention enduringly reduces hostility towards Muslims

Hostility towards outgroups contributes to costly intergroup conflict. Here, we test an intervention to reduce hostility towards Muslims, a frequently targeted outgroup. Our ?collective blame hypocrisy? intervention highlights the hypocrisy involved in humans? tendency to collectively blame outgroup but not ingroup members for blameworthy actions of individual group members. Using both within-subject and between-subject comparisons in a pre-registered longitudinal study in Spain, we find that our intervention reduces collective blame of Muslims and downstream anti-Muslim sentiments relative to a matched control condition, and that its effects persist one month and one year later. We replicate the intervention?s benefits in a second study. The intervention?s effects are mediated by reductions in collective blame and moderated by individual differences in Preference for Consistency. Together, these data illustrate that the collective blame hypocrisy intervention enduringly reduces harmful intergroup attitudes associated with conflict escalation, particularly among those who value consistency in themselves and others.