Truth by Repetition … without repetition: Testing the effect of instructed repetition on truth judgments

Mattavelli, S., Corneille, O., & Unkelbach, C.

Journal of Experimental Psychology

Learning Memory and Cognition

June 2022

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. In three preregistered experiments (N=684), we examined the effect of merely instructed repetition (i.e., not experienced) on truth judgments. Experiments 1-2 instructed participants that some statements were present (vs. absent) in an exposure phase allegedly undergone by other individuals. We then asked them to rate such statements based on how they thought those individuals would have done. Overall, participants rated repeated statements as more true than new statements. The instruction-based repetition effects were significant but also significantly weaker than those elicited by the experience of repetition (Experiments 1 & 2). Additionally, Experiment 2 clarified that adding a repetition status tag in the experienced repetition condition did not impact truth judgments. Experiment 3 further showed that the instruction-based effect was still detectable when participants provided truth judgments for themselves rather than estimating other people’s judgments. We discuss the mechanisms that can explain these effects and their implications for advancing our understanding of the truth effect.

(Beginning of the) General Discussion 

Deciding whether information is true or false is a challenging task. Extensive research showed that one key variable that people often use to judge the truth of a statement is repetition (e.g., Hasher et al. 1977): repeated statements are judged more true than new ones (see Dechêne et al., 2010). Virtually all explanations of this truth effect refer to the processing consequences of repetition: higher recognition rates than new statements, higher familiarity, and higher fluency (see Unkelbach et al., 2019). However, in many communication situations, people get to know that a statement is repeated (e.g., it occurred frequently) without prior exposure to the statement. Here, we asked whether repetition can be used as a cue for truth without prior exposure, and thus, in the absence of experiential consequences of repetition such as fluency. 

Conclusion 

This work represents the first attempt to assess the impact of instructed repetition on truth judgments. We found that the truth effect was stronger when repetition was experienced rather than merely instructed in three experiments. However, we provided initial evidence that a component of the effect is unrelated to the experience of repetition. A truth effect was still detectable in the absence of any internal cue (i.e., fluency) induced by the experienced repetition of the statement and, therefore, should be conditional upon learning history or naïve beliefs. This finding paves the way for new research avenues interested in isolating the unique contribution of known repetition and experienced fluency on truth judgments.

The research is here.

This research has multiple applications to psychotherapy, including how do patients know what information about self and others is true, and how much is due to repetition or internal cues, beliefs, or feelings.  Human beings are meaning makers, and try to assess how the world functions based on the meaning projected toward others.

Truth by Repetition: Explanations and Implications

Unkelbach, C., Koch, A., Silva, R. R., & Garcia-Marques, T. (2019).
Current Directions in Psychological Science, 28(3), 247–253. https://doi.org/10.1177/0963721419827854

Abstract

People believe repeated information more than novel information; they show a repetition-induced truth effect. In a world of “alternative facts,” “fake news,” and strategic information management, understanding this effect is highly important. We first review explanations of the effect based on frequency, recognition, familiarity, and coherent references. On the basis of the latter explanation, we discuss the relations of these explanations. We then discuss implications of truth by repetition for the maintenance of false beliefs and ways to change potentially harmful false beliefs (e.g., “Vaccination causes autism”), illustrating that the truth-by-repetition phenomenon not only is of theoretical interest but also has immediate practical relevance.

Here is a portion of the closing section:

No matter which mental processes may underlie the repetition-induced truth effect, on a functional level, repetition increases subjective truth. The effect’s robustness may be worrisome if one considers that information nowadays is not randomly but strategically repeated. For example, the phenomenon of the “filter bubble” (Pariser, 2011) suggests that people get verbatim and paraphrased repetition only of what they already know and believe. As discussed, logically, this should not strengthen information’s subjective truth. However, as discussed above, repetition does influence subjective truth psychologically. In combination with phenomena such as selective exposure (e.g., Frey, 1986), confirmation biases (e.g., Nickerson, 1998), or failures to consider the opposite (e.g., Schul, Mayo, & Burnstein, 2004), it becomes apparent how even blatantly false information may come “to fix itself in the mind in such a way that it is accepted in the end as a demonstrated truth” (Le Bon, 1895/1996). For example, within the frame of a referential theory, filter bubbles repeat information and thereby add supporting coherent references for existing belief networks, which makes them difficult to change once they are established. Simultaneously, people should also process such information more fluently. In the studies reviewed here, statement content was mostly trivia. Yet, even for this trivia, participants evaluated contradictory information as being less true compared with novel information, even when they were explicitly told that it was 100% false (Unkelbach & Greifeneder, 2018). If one considers how many corresponding references the information that “vaccination leads to autism” may instigate for parents who must decide whether to vaccinate or not, the relevance of the truth-by-repetition phenomenon becomes apparent.