Once we hold a belief, we search for, favor, and recall evidence that supports it, while discounting what contradicts it. We feel like we’re reasoning; we’re often just defending.
Confirmation bias: we seek, notice, and remember evidence that fits what we already think — and quietly ignore what doesn’t.
Think a coworker is unreliable, and you’ll notice every late reply and forget every on-time one. Believe a stock will rise, and the bullish articles feel insightful while the bearish ones feel like noise. The evidence didn’t change — your filter did.
Psychologist Peter Wason, who coined the term, showed that people test their ideas by looking for confirmations rather than trying to break them. Given a rule to discover, his subjects kept proposing examples that fit their guess instead of examples that might prove it wrong — and so they stayed wrong longer. We treat our beliefs as things to defend, not hypotheses to test.
To think more clearly, deliberately go looking for the evidence that would prove you wrong, and take the strongest version of the other side seriously. Ask: “What would change my mind — and have I honestly looked for it?” A belief that survives a real attempt to disprove it is worth far more than one you only ever confirmed.
It’s the bias most likely to keep a smart person confidently wrong — and the antidote, seeking disconfirmation, is a habit you can build.
Read as “people ignore facts.” It’s sneakier: we seek, interpret and remember information in ways that favor what we already believe — often while feeling perfectly objective. You can’t spot it from the inside, which is why the fix is structural (seek disconfirming evidence on purpose), not just “be open-minded.”
Try to answer in your head first — that effort is what builds the memory.
Lock this idea into memory with a 5-minute active-recall session — the science of spaced repetition, no signup.
Try this idea free →One tap adds it to your review queue — we bring it back right before you’d forget. No signup.