Truth by repetition … Without repetition: Testing the effect of instructed repetition on truth judgments.

Abstract

Past research indicates that people judge repeated statements as more true than new ones. An experiential consequence of repetition that may underly this "truth effect" is processing fluency: processing statements feels easier following their repetition. Here, we examine the effect of merely instructed (i.e., not experienced) repetition on truth judgments, which we compared to the effect of factual repetition. In two preregistered experiments (N=468), we found a larger truth effect for factual repetition compared to instructed repetition. However, we also found a non-experiential contribution to truth judgments: statements instructed to be repeated were judged more true than those instructed to be new. Experiment 2 further clarified that adding a repetition status tag in the factual repetition condition did not impact truth judgments. Moreover, for both experienced and instructed repetition, the effect on truth was qualified by subjective recognition. We discuss the mechanisms that can explain the impact of instructed repetition on truth and its implications for a better understanding of the truth effect.

People underestimate the influence of repetition on truth judgments (and more so for themselves than for others)

“…In support of the role of beliefs, Mattavelli et al (2022) found a truth effect even when repetition was dissociated from experience; that is, when participants rated the truth value of statements that were merely told to be repeated vs. new (while not being actually repeated or not).…”

“…One hundred and thirty participants (79 females, 51 males, Mage = 39.10, SDage = 11.54) were recruited via Prolific Academic and paid £ 0.63 for their participation. We applied five screening criteria: participants declaring to be English speakers, to live in the United States, have an approval rate of at least 95%, have at least 100 previous submissions on Prolific, and did not take part in previous related studies (Mattavelli et al, 2022).…”

Irrelevant information enhances a sense of knowledge and curses our understanding of other minds.

“…It was suggested that an affirmative tag makes the claim more believable and increases its memorability and retrievability, biasing the individual toward a "true" judgment. In a recent study, Mattavelli et al (2023) demonstrated that participants gave higher truthiness ratings for statements which were said to have been repeated for other participants than statements without alleged repetition. Hence, enhanced truthiness judgments could result from "merely instructed repetition" without the experience of repetition.…”

No Moral Truth in the Mind: Moral Judgments Do Not Tap Cognitive Processes That Are Involved in Assessing Truth-Value

“…In line with previous research, we also predict that truth judgments are related to memory for statement repetition. Specifically, we predict (a) that the truth effect increases with better discrimination between old and new statements (e.g., Silva et al, 2017) and (b) that participants judge new statements that they think were repeated as more certainly true than new statements that they think were not repeated (e.g., Mattavelli et al, 2022). To test whether moral judgments rely on processes involved in assessing perceived truth-value, we compare the moral repetition effect and the truth effect and the relation of moral judgments and truth judgments to memory for statement repetition.…”

“…Referential memory networks presumably lead to higher fluency experiences and to remembering a statement. Yet, merely believing that one saw a statement beforethat was in fact not repeatedseems to increase the perceived truth of the statement, too (Mattavelli et al, 2022; see also Bacon, 1979). The perceived truth-value of a statement therefore seems to be informed by fluency but also by memory of a statement.…”