Current Directions in Psychological Science, 28(3), 247–253. https://doi.org/10.1177/0963721419827854
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.