The role of valence matching in the truth-by-repetition effect

People judge repeated information as truer than new information, a "truthby-repetition" effect. Because repetition increases processing fluency, which is assumed to elicit positive affect, participants may match their positive experience associated with repeated information with a positive ("true") rather than negative ("false") response. We tested this valencematching hypothesis in a preregistered experiment by manipulating the affective congruency of the response format. Specifically, in the congruent condition, participants had to select a positive (negative) picture to respond "true" ("false"). In the incongruent condition, we reversed these associations. In line with the valence matching hypothesis, the truth-by-repetition effect was larger in the congruent than incongruent condition. However, the effect was small, and Bayesian analyses were inconclusive. In addition, the truth-by-repetition effect was significant in both response format conditions. The results suggest a possible contribution of a valence matching process to the truth-by-repetition effect, but one that does not challenge extant models.