Explaining Away the Illusion of Consensus

Consensus among sources often signals a claim’s trustworthiness. However, when all sources simply echo information from a single origin, an “illusion of consensus” can arise, leading individuals to feel equally convinced by a dependent consensus (a single, repeatedly cited source) as by an independent consensus (corroborated information from multiple sources), unless their independence is made clear. This effect may occur because repetition can be perceived as a cue for credibility; thus, undermining source credibility might prompt individuals to discount a dependent consensus. We conducted three experiments to test whether whether explaining that source repetition resulted from biases in source selection can enable people to discount a dependent consensus. Participants engaged in a political polling task to assess confidence in claims supported by an independent consensus (news outlets citing different polling companies), a dependent consensus without explanation (news outlets citing the same polling company), or a dependent consensus accompanied by explanations that either boosted or undermined source credibility. While an independent consensus was more persuasive than dependent consensus, explanations alone did not affect claim confidence (Experiments 1-2a, 2b). In Experiment 3, when participants generated their own explanations for why source repetition might undermine reliability, confidence in claims supported by a dependent consensus was reduced. These findings suggest that social inference processes contribute to the illusion of consensus, with implications for interventions designed to mitigate the impact of misleading claims repeated in media.