Psychological Vaccination: How Counter-Narratives Combined with Inoculation Reduce Agreement with Antisemitic Content Online

In a randomized experiment (N=4,893), we tested four video interventions against antisemitic messages among young adults. Only videos combining inoculation with counter-narratives effectively reduced agreement (-7.3%), operating through a vaccine-like process: triggering protective disgust responses (+19%) while building psychological resistance. Results demonstrate how strategic messaging can preemptively combat harmful content.