Illusory Truth Effect
Repetition raises believability even when it adds no evidence.
Evidence: well established. We label every concept honestly, and say so when it's a teaching model. How we rate evidence.
Shrink Definition
The illusory truth effect is the tendency to rate a statement as more true simply because we have heard it before. Repetition makes a claim easier to process, and that ease gets mistaken for accuracy. It works even when we know better, and even for claims we could check. Familiarity quietly stands in for evidence.
Plain language
The more often we hear something, the truer it starts to feel.
Shrink Insight
Your brain reads fluency as truth, so a familiar claim can beat an unfamiliar fact.
Why it matters
It underlies how rumors, ads, and misinformation take hold, and it shapes how beliefs about health and self form. Spotting it lets you separate what you have verified from what you have simply heard a lot.
Common misunderstanding
People think only the gullible fall for repeated claims. The effect appears even in people who hold accurate knowledge on the topic.
Shrink Perspective
Hearing something many times isn't the same as checking it once.
Shrink Reflection
Which of my beliefs rest on repetition rather than evidence?
Shrink Step
When a claim feels obviously true, ask whether you have verified it or just heard it often.
Shrink Minute
Name one belief you hold mostly because it's repeated around you.
Shrink Takeaway
Familiar isn't the same as true.
Medical boundary
This concept is educational and shouldn't be used to self-diagnose. It doesn't replace care from a licensed clinician. Symptoms, medication, and treatment decisions should be discussed with a qualified professional, and emergency symptoms require emergency care.
Evidence summary
One of the more reliably replicated findings in cognitive psychology, demonstrated across decades and many kinds of statements.
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