Alluring or Alarming? The Polarizing Effect of Forbidden Knowledge in Political Discourse

"Forbidden knowledge" claims are central to conspiracy theories, yet they have received little systematic study. Forbidden knowledge claims imply that information is censored or suppressed. Theoretically, forbidden knowledge could be alluring or alarming, depending on alignment with recipients' political worldviews. In three studies (N = 2363, two preregistered), we examined censorship claims about (conservative-aligned) controversial COVID-19 topics. In Studies 1a and 2 participants read COVID-19 claims framed as censored or not. Conservatives reported more attraction to and belief in the claims, regardless of censorship condition, while liberals showed decreased interest and belief when information was presented as censored. Study 1b revealed divergent interpretations of suppression motives: liberals assumed censored information was harmful or false, whereas conservatives deemed it valuable and true. In Study 2, conservatives made more critical thinking errors in a vaccine risk reasoning task when information was framed as censored. Findings reveal the polarizing effects of forbidden knowledge frames.