Assessing How Fact-Checks Influence Accuracy and Consensus Judgments: Evidence From the Olympics.

Fact-checks have become a popular intervention aimed at tackling misinformation, yet concern has persisted related to the potential for fact-checking to inadvertently amplify false narratives-a phenomenon commonly referred to as a "backfire effect." At the same time, recent evidence from research on repeated claims has suggested that there is a risk that fact-checks may also generate misperceptions regarding societal beliefs-or an "illusory consensus" effect. This paper presents findings from an ecologically valid two-wave experimental study that tested whether repeated fact-checking interventions could cause either of these negative outcomes. To further enhance the validity of the design, we draw on quota-balanced samples of participants from the United States, France, and South Africa (N = 680), who were presented with a set of true and false posts taken from online discussions regarding the 2024 Summer Olympic Games in Paris, France. Outcome measures focused on personal accuracy judgments (i.e., how accurate participants deemed each claim) and consensus estimates (i.e., whether their fellow citizens would believe each claim). After the Olympics concluded, participants were asked to assess both new and previously reviewed statements. Consistent with prior work, results indicate no evidence of the backfire effect (