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.
- 1 min read
- 1 book teaches this
- 6 linked ideas
Why does the cognitive dissonance happen?
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.
What does the cognitive dissonance look like in real life?
- 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 do you counter the cognitive dissonance?
- 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.
Keep reading
Nocebo effect
The nocebo effect is when negative expectations about a treatment or situation cause real unpleasant symptoms or make existing ones worse, even if the…
Go deeper
Affiliate links. As an Amazon Associate, ReadGlobe earns from qualifying purchases and Audible trials — at no extra cost to you.
The book behind this idea: Mistakes Were Made (But Not by Me) by Carol Tavris & Elliot Aronson. Hear the whole thing free — start an Audible trial and your first audiobook is on the house.
Read the full summary of Mistakes Were Made (But Not by Me) →
More canonical picks:
- Thinking, Fast and Slow — Daniel Kahneman
- The Art of Thinking Clearly — Rolf Dobelli
- The Great Mental Models, Volume 1 — Shane Parrish
- Poor Charlie’s Almanack — Charlie Munger
- Super Thinking — Gabriel Weinberg & Lauren McCann
- Seeking Wisdom — Peter Bevelin
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.