Conspiracy thinking and belief in partisan conspiracy theories: A moderating effect of partisan congruence?

Various studies have shown that people's predisposition to believe in conspiracy theories, commonly referred to as “conspiracy thinking,” strongly predicts belief in a myriad of conspiracy theories. Research also shows that partisan affiliations shape conspiracy theory beliefs: people tend to embrace theories that portray their political opponents as conspirators, while rejecting those that implicate their side. In this paper, we theorize that one's conspiracy thinking and partisan affiliations interact in predicting belief in partisan conspiracy theories. Specifically, we argue that the effect of conspiracy thinking is moderated by one's partisan affiliation, such that this effect is stronger when the conspiracy theories are congruent with one's partisan affiliations than when they are incongruent. Drawing on six studies from the US and Israel (total N = 10,765; 61 conspiracy theories in total), we find strong and consistent support for our argument. In addition, we find no interactive effect when predicting belief in non-partisan conspiracy theories. We conclude by discussing the implications of these findings for the study of conspiracy theory endorsement.