Repetition, not photos, drives belief in true and false claims

Repeating a statement makes people more likely to believe it, whether the statement is true or false. This phenomenon, known as the illusory truth effect, has been documented for general trivia, political news headlines, and health-related claims. A new study led by Jae Kwon and Lisa K. Fazio, published in Cognitive Research: Principles and Implications, asked a deceptively simple follow-up question: what happens when repetition is paired with photographs, another factor known to sway belief?

Photos are thought to influence belief through a mechanism similar to the one behind the illusory truth effect. According to the fluency account, repetition makes a statement easier to process, and that ease of processing is then used as a cue for truth. Pictures can operate on the same channel: semantically related photos have been shown to increase belief in a statement, while unrelated photos can decrease it. If both effects run on processing fluency, the researchers reasoned, then adding related or unrelated photos might amplify or reduce the effect of repetition on perceived truth.

To test this, the team ran three experiments. In the first, 151 participants rated the truth of trivia statements presented under three photo conditions: a related photo, an unrelated photo, or no photo at all. The second experiment turned to political news headlines, with 201 participants rating headlines shown either with a related photo or without one. The third experiment was the largest, with a total of 604 participants rating trivia statements under two photo conditions, related or none, across two stimulus sets, one presented with repetition and one without.

The results were strikingly one-sided. Across the experiments, repetition reliably increased belief, both for trivia statements and for political headlines. The photos, by contrast, did not influence belief at all. And crucially, there was no interaction between the two factors: adding a related photo did not strengthen the effect of repetition, and an unrelated photo did not weaken it.

The authors offer an interpretation that will resonate with anyone who has watched misinformation spread online. When two factors operating through a similar mechanism are both present during belief formation, the dominant effect, in this case repetition, may simply overshadow the weaker one, the presence of a photo. Repetition acts as the louder signal in the fluency-based system that people use to judge truth.

Perhaps more surprising is what the third experiment revealed about photos on their own. Even without the masking effect of repetition, when participants saw statements only once, the effect of photos on belief remained weak. A picture that was semantically related to the text did not measurably move people’s truth judgments in this setting.

The findings carry practical weight for understanding the modern information environment. People spend substantial time on social media, repeatedly encountering an abundance of both true and false content, and they rely on these platforms not only for entertainment but to learn about important issues such as health and politics. That circulating content is typically presented with both text and images, making the interplay between verbal and visual information directly relevant to how beliefs form at scale.

For communicators, educators, and platform designers, the message is double-edged. Repeated exposure to information in a media-rich environment can be a powerful driver of belief, which underscores why repeated falsehoods are so difficult to dislodge. At the same time, simply adding photos to a message may not make it seem more credible, at least under the conditions tested here, which included trivia statements and political headlines rated by several hundred participants in controlled online experiments.

As with any set of experiments, scope matters. The studies examined specific stimulus types, trivia and political headlines, and specific photo conditions, and the abstract reports overall patterns rather than guarantees about every context. But the core conclusion is clear: in the contest between repetition and imagery as drivers of perceived truth, repetition wins, and the photo effect, long assumed to be a reliable companion cue, barely registers.

Subject of Research: How repetition and accompanying photos affect belief in trivia statements and political headlines

Article Title: The interplay between verbal and visual information: how repetition and photos influence belief

Article References: Kwon, J., & Fazio, L. K. (2026). The interplay between verbal and visual information: how repetition and photos influence belief. Cognitive Research: Principles and Implications. https://doi.org/10.1186/s41235-026-00757-3

Image Credits: AI Generated

DOI: 10.1186/s41235-026-00757-3

Keywords: illusory truth effect, repetition, processing fluency, photos, belief, misinformation, political headlines, trivia statements, social media, cognitive psychology, interplay, between