Intergroup psychological interventions highlighting commonalities can increase the perceived legitimacy of critical voices.

With rising risks to democracy, the delegitimization of political actors that criticize state policies is increasing worldwide. Our research examines what intergroup psychological interventions can contribute to the (re)legitimization of these critical voices. We consider two approaches to legitimization, as a process involving the recategorization of a target from illegitimate to legitimate: (1) interventions encouraging recategorization of societal actors based on common preferences, values and/or the common ingroup identity; and (2) interventions highlighting inconsistencies between delegitimizing attitudes and ingroup identity, values or interest. An intervention tournament among 1691 Jewish Israelis tested several interventions, based on real information, against a generic Control condition. The results of a mixed-effects model revealed that two interventions, highlighting commonalities between the delegitimized group and mainstream attitudes and values, were effective in increasing the group's perceived legitimacy. These interventions, emphasizing common interests (e.g., supporting communities, reducing disparities in the provision of health services) and common values (e.g., human dignity, fair due process), can be applied to amplify and include critical voices as part of the effort to combat the harmful consequences of democratic backsliding.