Illusory Truth Effect
The illusory truth effect is the tendency to judge a repeated statement as more true than a comparable unfamiliar statement.
Established ConceptWhat does it mean in everyday language?
Hearing something again can make it feel more credible, even when the repetition adds no evidence. Familiarity can be mistaken for a reason to believe.
An example
Hypothetical example: the same unsupported claim appears in several generated summaries. A reader begins to rate it as more plausible because it sounds familiar.
A more precise definition
The illusory truth effect is an increase in perceived truth associated with prior exposure to a statement. Researchers measure it by comparing truth judgments for repeated and new statements under controlled conditions.
Key features
- Concerns judged truth rather than objective accuracy
- Can arise without new supporting evidence
- Is usually measured by comparing repeated and unfamiliar statements
Where the definition stops
It does not mean that repetition makes every claim believable or changes everyone's mind. Repetition, prior knowledge, plausibility, and attention can interact.
How it relates to synthetic imprinting
It offers an existing explanation to test when repeated synthetic messages affect belief. A later follow-up is needed to determine whether any change persists.
Research context
Fazio and colleagues found that prior knowledge did not eliminate repetition-related truth judgments in their experiments. That result does not establish that knowledge or careful checking is always ineffective.
Related terms
- Processing Fluency Established Concept
- Mere-Exposure Effect Established Concept
- Misinformation Established Concept
Sources and further reading
- Knowledge does not protect against illusory truth. — Lisa K. Fazio, Nadia M. Brashier, B. Keith Payne, Elizabeth J. Marsh (2015). Journal of Experimental Psychology: General.
Cite this definition
APA: SyntheticImprinting.com. (2026). Illusory Truth Effect. https://syntheticimprinting.com/terms/illusory-truth-effect/
MLA: “Illusory Truth Effect.” SyntheticImprinting.com, 2026, https://syntheticimprinting.com/terms/illusory-truth-effect/. Accessed September 26, 2026.
Chicago: SyntheticImprinting.com. “Illusory Truth Effect.” Last modified 2026-09-24. https://syntheticimprinting.com/terms/illusory-truth-effect/.
What the status means
A concept used in academic or professional literature. This label does not mean every claim about it is settled.
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