Cognitive dissonance
Cognitive dissonance is the mental discomfort of holding two conflicting beliefs, or of acting against your beliefs. To relieve the tension we change one of them — usually by rationalising the action rather than admitting we were wrong.
Why it happens
The mind craves consistency between beliefs, attitudes, and actions. A clash creates genuine psychological tension, and the easiest way to resolve it is rarely to change behaviour — it is to adjust the belief, downplay the conflict, or invent a justification that restores harmony.
The harder something is to undo, the more your mind insists it was right — dissonance turns sunk costs into convictions.
Examples
- A smoker who knows smoking is harmful decides "the research is overblown" rather than quit.
- After a hard, expensive choice, you suddenly notice all the reasons it was the right one (effort justification).
- Buying something pricey, then reading reviews only to reassure yourself it was a good purchase.
How to counter it
- Notice the discomfort itself as a signal — it often means a belief is being protected from evidence.
- Separate "I made a mistake" from "I am a failure"; the first is survivable, and the second is what dissonance defends against.
- When belief and action conflict, let the action — not the story — be the thing you change.
The deeper point
Its most counterintuitive effect: the harder something is to undo — the more you paid, suffered, or publicly committed — the more your mind insists it was right. Dissonance quietly turns sunk costs into convictions.
Frequently asked
- What is a simple example of cognitive dissonance?
- Believing you are honest, then telling a lie — the clash is uncomfortable, so you reframe the lie as "harmless" or "necessary" to keep your self-image intact.
- Who discovered cognitive dissonance?
- Psychologist Leon Festinger, in the 1950s, after studying a doomsday cult that strengthened its beliefs when the predicted apocalypse failed to arrive.
- How is cognitive dissonance related to confirmation bias?
- Confirmation bias is often a tool for avoiding dissonance: by filtering out conflicting evidence, you prevent the uncomfortable clash from arising in the first place.
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Cite this page
ReadGlobe. (2026). Cognitive dissonance. https://readglobe.com/bias/cognitive-dissonance/
"Cognitive dissonance." ReadGlobe, 29 May 2026, readglobe.com/bias/cognitive-dissonance/.
Primary source: Wikipedia
Editorial synthesis © ReadGlobe 2026, drawing on Kahneman’s Thinking, Fast and Slow, the Tversky–Kahneman research program, and the primary cognitive-science literature. · Last reviewed 2026-05-29.