If you'd just like a quick definition of the confirmation bias instead of its whole backstory, here it is:

A confirmation bias is a person's tendency to look for, see, accept, and remember things that confirm (or fit with) the thoughts, beliefs, and values that they already hold, as opposed to things that contradict those thoughts, beliefs, or values.

Say I believe that everyone I interact with in Richmond is friendly to me.

Everywhere I go in Richmond, I meet friendly people. It happens over and over. But if I'm going to evaluate whether my belief is correct (Really? Are ALL Richmonders friendly to me ALL the time?) then I can't pay attention only to the friendly ones, because they won't confirm whether or not I'm completely correct, even if I meet them by the hundreds. I have to keep my eyes open, also, to any UNfriendly Richmonders. One friendly Richmonder can't verify my belief, and neither can a thousand. But a single unfriendly Richmonder can falsify my belief, and until I at least try to find one, I can't conclude that my belief is right.

As the psychologist G. H. Von Wright put it, in order to think clearly and arrive at correct conclusions, you have to embrace "the fundamental... fact that no confirming instance of a law is a verifying instance, but that any disconfirming instance is a falsifying instance."

In 1960, the psychologist Peter Cathart Wason set out to see whether or not intelligent young college students would put that notion into practice on their own: the notion that "no confirming instance of a law is a verifying instance, but that any disconfirming instance is a falsifying instance." Would these students show "a willingness to attempt to falsify hypotheses, and thus to test those intuitive ideas which so often carry the feeling of certitude"?

Mostly, nope. They showed a confirmation bias instead. They tended to confirm their hypotheses instead of testing them.

Here's how it happened. He sat with each student one at a time and said:

You will be given three numbers which conform to a simple rule that I have in mind. This rule is concerned with a relation between any three numbers and not with their absolute magnitude, i.e. it is not a rule like all numbers above (or below) 50, etc.

Your aim is to discover this rule by writing down sets of three numbers, together with reasons for your choice of them. After you have written down each set, I shall tell you whether your numbers conform to the rule or not, and you can make a note of this outcome on the record sheet provided. There is no time limit but you should try to discover this rule by citing the minimum sets of numbers.

Remember that your aim is not simply to find numbers which conform to the rule, but to discover the rule itself. When you feel highly confident that you have discovered it, and not before, you are to write it down and tell me what it is. Have you any questions?

The numbers he gave them were "2, 4, and 6," and the secret rule to be discovered was "numbers that ascend in order." For example, if a student wrote down "1, 19, 215," then Wason would reply, "Those numbers do conform to the rule." And if they wrote "100, 98, 96," then Wason would reply, "Those numbers do not conform to the rule."

By the way, do you think you'd be good at this game? Welp, we can't test it now. I've already spoiled it by mentioning the secret strategy to winning: you've got to come up with a hypothesis and then try to falsify it.

The few students who played the game well did try to falsify their hypotheses so that they could discover the rule. That is, if they hypothesized that the rule might be "even consecutive numbers," then they would try even nonconsecutive numbers (like "4, 8, 12"), or odd consecutive numbers (like "3, 5, 7") to see what conformed to the rule, and adjust their hypotheses accordingly. 

Most students didn't do that. If they thought the rule might be "even consecutive numbers," then they just kept seeking more and more confirmations with sets like "14, 16, 18" or "100, 102, 104." As this supposedly confirmatory evidence piled up, the students felt certain that their hypothesized rules were correct. They didn't realize that they needed to seek out data that falsified them.

"The results," Wason concluded, "show that very few intelligent young adults spontaneously test their beliefs in a situation which does not appear to be of a 'scientific' nature."

Instead, they're biased toward confirming their beliefs.

Wason didn't use the phrase "confirmation bias" in that 1960 study, but he continued studying and exploring how people prefer to confirm instead of falsify their beliefs, and by 1977 other psychologists were referring to that preference as the "confirmation bias."

To sum this up, someone's confirmation bias is their habit of seeking out, noticing, understanding, favoring, and remembering things that confirm what they already think, believe, or value. In other words, when you only see and hear what you want to see and hear because those things make sense to you and don't challenge your thinking, and when you give no thought to seeking out information that might falsify your thinking, you're demonstrating the confirmation bias.

Part of speech:

Noun, both the countable kind ("They're demonstrating the confirmation bias") and the uncountable kind ("They're studying confirmation bias").

Other forms: 

None are common.

how to use it:

"Confirmation bias" is one of those rare but ultra-specific phrases that help you quickly label someone's faulty thinking, maybe your own. It's a faster, more formal, more precise way of saying "People see what they want to see," "People hear what they want to hear," and "People believe what they want to believe."

You might say that, in some situation, your confirmation bias led you astray, blinded you to the truth, or stopped you from digging deeper. Or you might say that your confirmation bias tainted, affected, or ruined your thinking.

If you're not sure your readers will be familiar with this phrase, you may want to gloss it for them: quickly define it right after you use it. We'll see an example of glossing below, from the New York Times.

examples:

"The strongest bias in American politics is not a liberal bias or a conservative bias; it is a confirmation bias, or the urge to believe only things that confirm what you already believe to be true... The only way people will start rejecting falsehoods being fed to them is by confronting uncomfortable truths."
   — Emma Roller, New York Times, 25 October 2016

"The detailed advertising tools built into many social media platforms let disinformation campaigners exploit confirmation bias by tailoring messages to people who are already inclined to believe them."
  — Giovanni Luca Ciampaglia and Filippo Menczer, Salon, 23 June 2018

has this page helped you understand "confirmation bias"?

Awesome, I'm glad it helped!

Thanks for letting me know!
If you have any questions about this term, please message me at Liesl@HiloTutor.com.

study it:

Explain the meaning of "confirmation bias" without saying "way of perceiving that supports your own beliefs" or "way of thinking that reaffirms your own opinions."

try it out:

See if you can give an example of a news story or headline that triggers your confirmation bias.

In other words, what kind of headline might you read and immediately accept as accurate, because it matches what you already think? Would you be willing to read that article and hunt for information that might falsify your belief?

For example, if I see the headline "Some Sugars Less Bad Than Others," that triggers my confirmation bias: I love sweet foods and believe they're not too unhealthy if eaten in moderation, so I'm totally ready to accept the headline. But if I have five or ten minutes, I might be willing to read the whole article and hunt for facts that could falsify my belief. I just won't enjoy it!

If you like, use this space to write. (To save your work, copy and paste it into an email or a document.)

before you review, play:

Try to spend 20 seconds or more on the game below. Don’t skip straight to the review—first, let your working memory empty out.

Our game this month is "CLICKBAIT THIS!"

Summon your creativity and dismiss your sense of decency as you invent a clickbaity description: one that's urgent, exaggerated, ungrammatical, conspiratorial, utterly false, emotionally abrasive, vaguely revelatory, full of feigned shock, and/or bloated with capital letters, question marks, exclamation points, and/or emojis. Get in there and be shameless.

If you're sufficiently disgusted with your clickbait, share it with a friend and see if they can guess its subject. I'll also share mine with you to see if you can guess it.

Clickbait this today: A magazine or newspaper of your choice.

Try guessing my magazine or newspaper: BOUGHT BY BILLIONAIRE?? CLIMATE CHANGE NO BIGGIE?? [DARKNESS] [GONE ANTI-WOKE]

Scroll all the way down for the answer to mine.

review this term:

1. The opposite of a CONFIRMATION BIAS would be a DISCONFIRMATION BIAS or a FALSIFICATION BIAS, which would be a tendency to _____.

A. seek information that contradicts what you already know or feel
B. assume documents have been doctored or manipulated for nefarious purposes
C. reject applications who would have performed well in the jobs they were applying for

2. Writing for Forbes, Bryce Hoffman recommends fending off the confirmation bias with _____.

A. deep breaths and a count of ten
B. reflection, critical thinking, and peer review
C. recycling, composting, and choosing experiences over material goods

Answers to the review questions: 1. A 2. B From the game: the Washington Post.

a final word:

I hope you're enjoying Make Your Point. It's made with love. I'm Liesl Johnson, a reading and writing tutor on a mission to explore, illuminate, and celebrate words. From my blog: On vocabulary...       36 ways to study words.       Why we forget words, & how to remember them.       How to use sophisticated words without being awkward. On writing...       How to improve any sentence.       How to motivate our kids to write.       How to stop procrastinating and start writing.       How to bulk up your writing when you have to meet a word count. From my heart: a profound thanks to the generous patrons, donors, and sponsors that make it possible for me to write these emails. If you'd like to be a patron or a donor, please click here. If you'd like to be a sponsor and include your ad in an issue, please contact me at Liesl@HiloTutor.com. A disclaimer: When I write definitions, I use plain language and stick to the words' common, useful applications. If you're interested in authoritative and multiple definitions of words, I encourage you to check a dictionary. Also, because I'm American, I stick to American English when I share words' meanings, usage, and pronunciations; these elements sometimes vary across world Englishes.