Illusory truth effect
The tendency to believe a statement is true after hearing it several times. Repetition makes a claim feel familiar and easy to process, and that ease gets mistaken for accuracy.
In everyday life
A false health tip shared again and again on social media starts to feel like common knowledge, even to people who once doubted it.
You've heard in ads, from coworkers, and on podcasts that people only use a small part of their brains, and by now it simply feels like a fact, though you've never checked.
Why your mind does this
We take in far more than we can handle, so the brain uses what is already active in memory as a filter. Things we met recently, often, or with strong feeling are likely to matter again, so pushing them forward saves time and effort.
Its family, in 30 seconds: Primed & repeated
How to spot it
Ask yourself whether you believe this because you have seen evidence or because you have heard it so often.
How to counter it
When a claim feels obviously true, trace it back to its original source before you repeat it.