Repeating statements increases their perceived truth. Yet, whether repetition enhances the credibility of their source remains unexplored. We examined a repetition-induced source credibility effect in four preregistered experiments. In Experiment 1 (N = 90), we exposed participants to 20 unrepeated and 20 repeated statements communicated by 40 individuals. Repetition significantly increased both statement truth and source credibility. Experiment 2 (N = 65) tested if the increase in source credibility generalizes to new contexts. After rating the truth of repeated and unrepeated statements paired with different sources, participants judged novel statements from the same sources, showing increased credibility for sources previously associated with repeated statements. Experiment 3 (N = 180) did not replicate the effect without initial truth ratings. However, Experiment 4 (N = 435) resolved this inconsistency, showing a repetition-induced source credibility effect, regardless of participants’ task during source–statement pairings. We discuss the implications of these findings for illusory truth literature and persuasion and communication management.
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