Definition
Plain language
The way people start to believe a claim just because they've heard it repeated.
As stated in the literature
A well-documented psychological phenomenon in which repeated exposure to a statement increases perceived truthfulness, even when initially recognized as false.
Why it matters: It explains why AI systems that confidently repeat the same wrong answer can shift what users believe, even when those users initially doubted the claim.
For example, hearing the same dubious health claim repeated across several podcasts makes listeners rate it as more plausible than they did the first time.
Heard on the show
“There's a well-studied phenomenon called the illusory truth effect, where if you repeat a false claim to a person enough times, they start to believe it — even if they knew it was false at the start.”Episode 043 — When 'This Is False' Doesn't Stick: Why Models Learn the Lie Anyway