The Dual Impact of Believing and Spreading Conspiracy Theories: Independent and Interactive Effects on Social...

Prior research suggests that people who believe in and spread conspiracy theories are often viewed negatively, yet investigations systematically disentangling both factors are scarce. The present research addressed this gap through two pre-registered experiments with representative samples from the United States. In Study 1, 418 participants evaluated eight fictional individuals across 3,344 trials, presented as (a) believing in and/or (b) spreading conspiracy theories in a 2 × 2 within-subjects design. Analyses revealed that both characters who believed in conspiracy theories and those who spread them were perceived as less competent, moral, and warm, and as more narcissistic, Machiavellian, and psychopathic. Moreover, both believers and spreaders were perceived as likely to engage in conspiratorial actions themselves, and participants reported lower willingness to interact with them. However, significant interactions for all variables showed that these effects were particularly pronounced for characters who spread conspiracy theories without believing in them. Notably, participants' own conspiracy beliefs and, to some extent, their right-wing political orientation attenuated several effects and reversed some. In Study 2, we employed the reverse-correlation technique to model 412 participants' mental representations of individuals who varied in belief and/or spread of conspiracy theories using a 2 × 2 between-subjects design. Results were directionally consistent with Study 1-both believers and spreaders of conspiracy theories were mentally represented less favorably-but no interactions or moderations were observed. Moreover, believing had significantly stronger effects than spreading on the rating dimensions. We discuss the social implications of these results and outline future directions.