The Illusion of Consensus: A Failure to Distinguish Between True and False Consensus

When evaluating information, we cannot always rely on what has been presented as truth: Different sources might disagree with each other, and sometimes there may be no underlying truth. Accordingly, we must use other cues to evaluate information—perhaps the most salient of which is consensus. But what counts as consensus? Do we attend only to surface-level indications of consensus, or do we also probe deeper and consider why sources agree? Four experiments demonstrated that individuals evaluate consensus only superficially: Participants were equally confident in conclusions drawn from a true consensus (derived from independent primary sources) and a false consensus (derived from only one primary source). This phenomenon was robust, occurring even immediately after participants explicitly stated that a true consensus was more believable than a false consensus. This illusion of consensus reveals a powerful means by which misinformation may spread.