Repeating a False Claim About Chickens Makes People Believe It
Familiar, effortless information feels true, and repetition alone can create that feeling.
Veritasium · The Illusion of TruthJust hearing the phrase "the body temperature of a chicken" over and over makes people more likely to rate a false claim as true: that a chicken's body temperature is 34 degrees Celsius. The real number is closer to 41 degrees.
The reason is a feeling called cognitive ease, which reflects how much effort the brain is putting in. Things that are true, familiar, and effortless, like fire is hot or dogs have four legs, feel easy and good.
The trouble is that ease can be produced artificially, for example by repetition alone. Repeating a phrase, even without giving any useful information about it, makes it feel easier to take in. And things we keep encountering start to seem true.
Questions people ask
What exactly is cognitive ease?
Cognitive ease is the sense that something is easy to take in. Clear print, familiar words, and ideas you have seen before all increase it, and the brain tends to read that easy feeling as a sign that something is true, familiar, and good.
Does this happen with anything besides chickens?
Yes. The more often people encounter a claim, the more likely they are to judge it true, even when the repetition adds no new evidence for it.
How can I avoid falling for it?
Pause and check the claim against a reliable source, especially if it feels true simply because it sounds familiar. Ask where the evidence comes from, who benefits if you believe it, and whether you have actually verified it before sharing it.