What is Confirmation Bias? The Cognitive Bias of Seeing Only What You Believe

Definition

Confirmation bias is a psychological phenomenon where people seek out information that supports their existing beliefs while ignoring or underestimating information that contradicts them. Simply put, it's the tendency to "see only what you want to see."

For example, imagine a friend believes "Diet A is really effective!" They'll search the internet looking only for successful Diet A stories, thinking "I knew Diet A was the best!" But if they search the same way, they'll find dozens of Diet A failure cases too. Cases where it harmed people's health. However, the friend dismisses this information saying "They just didn't do it properly" or "That's a special case." This is confirmation bias.

Confirmation bias was proven by psychologist Peter Wason in the 1960s through experiments. He gave people the number pattern "2-4-6" and asked them to guess the rule. Most people thought "even numbers increasing by 2" and only tested numbers that fit their hypothesis, like "8-10-12." But the actual answer was just "ascending numbers." They only tested what matched their hypothesis and never tried the possibility they might be wrong.

Characteristics

• Operates unconsciously - It's not intentional. Your brain automatically pays more attention to information that matches your beliefs. We think we're objective, but we're actually biased
• Distorts information interpretation - Even looking at the same information, we interpret it to match our beliefs. Ambiguous evidence is interpreted favorably, and contradictory evidence is dismissed as "exceptional"
• Stronger in smarter people - Paradoxically, more intelligent or knowledgeable people can have stronger confirmation bias because they're better at creating logic to justify their beliefs
• Intensifies with emotion - The stronger the connection to identity, values, and self-esteem, the stronger the confirmation bias. We don't want to admit "I was wrong"
• Amplified in groups - When like-minded people gather (echo chamber), confirmation bias strengthens. They confirm each other's beliefs

Examples

Example 1: Political Beliefs Conservatives only watch conservative news, and progressives only watch progressive news. The same policy is reported as "economic revitalization" by conservative media and "burden on the common people" by progressive media. Since everyone watches media matching their beliefs, they think "I was right after all!" Opposing opinions are dismissed as "fake news" or "biased reporting." This makes political polarization worse.

Example 2: Investment Decisions When an investor believes "this company will definitely go up," only positive news catches their eye. New product launches, CEO's optimistic remarks, slight revenue increases... these things. Meanwhile, negative signals - competitors' advances, market share decline, insider selling - are dismissed as "temporary phenomenon" or "exaggerated rumors." Finally, when the stock price crashes, they think "Why didn't I see it?" Confirmation bias is one of the main causes of investment failures.

Example 3: Suspicion in Relationships When a partner starts to suspect infidelity, confirmation bias kicks in. Once they think "Is he/she cheating?", every action seems suspicious. Coming home late means "suspicious," not answering the phone means "hiding something?", buying new clothes means "who are they trying to impress?"... In reality, they were busy with work, in a meeting, and bought it on sale. Even affectionate gestures are interpreted as "being extra nice because they got caught?" This confirmation bias can destroy healthy relationships.

Example 4: Health Information Someone who believes "coffee is bad for health" only remembers research about coffee's side effects. Insomnia, acid reflux, heart palpitations... Someone who believes "coffee is good for health" only remembers research about coffee's benefits. Antioxidant effects, dementia prevention, metabolism boost... Even looking at the same research, we only accept what we want to believe. Most medical research concludes "it's okay in moderation" or "it varies by person," but we tend to seek extreme information.

Example 5: Job Interviews Suppose an interviewer liked a candidate in the first 5 minutes. Then, for the rest of the interview, only the candidate's good points are visible. "Good communication," "passionate," "rich experience"... On the other hand, if they didn't like the candidate initially, every answer seems negative. "Talks too much," "too confident," "experience is too diverse, lacks focus." It's the same answer, but interpretation changes completely based on first impressions.

How to Overcome

Confirmation bias can't be completely eliminated, but recognizing and reducing it is possible.

Step 1: Acknowledge First, accept that "I also have confirmation bias." The moment you think "I'm objective," you're more likely to be biased. Smart people, educated people, psychologists all have confirmation bias. Our brains are designed to work that way.

Step 2: Deliberately Seek Opposing Views Intentionally look for information that contradicts your beliefs. If you believe "A is good," search for "disadvantages of A." At first, it'll be uncomfortable and you'll feel resistance. You'll think "this is wrong information," "this is a biased view." That's confirmation bias at work. Endure that discomfort and read through.

Step 3: Ask "What If I'm Wrong?" Before making important decisions, ask yourself: "If I'm wrong, what evidence would there be?" "How can I confirm my thinking is wrong?" This question opens up the possibility of being wrong. It's the method scientists use when testing hypotheses.

Step 4: Use Devil's Advocate When making important decisions, ask friends or colleagues to deliberately take the opposing position. "Find flaws in my plan," "Tell me why this will fail." It might feel bad at first, but it can prevent big mistakes. Good organizations institutionalize this culture.

Step 5: Look at Numbers and Data Look at objective data rather than subjective feelings or anecdotes. Rather than "A worked well for people around me," look at "What's the success rate of A in national statistics?" Of course, data can also be selected selectively, but it's better than feelings.

Step 6: Separate Decision from Self "This opinion is wrong" and "I'm stupid" are different things. When your opinion becomes identified with your self, it becomes too difficult to admit you're wrong. Think "I'm still a good person. I just thought wrong about this case."

Step 7: Look at Diverse Sources Don't just look at one media or one perspective. Look at conservative and progressive newspapers, domestic and international news. It's a headache at first, but you'll gain a more multi-dimensional perspective.

Step 8: Remember Past Wrong Experiences Write down experiences where you were confident but turned out to be wrong. Those "I was really sure then but was wrong" experiences. Recalling these gives you room to doubt your current confidence.

Step 9: Take Time Don't make important decisions immediately. Think again after a day or two. When first impressions and emotions settle, you can see more objectively. It's normal to think "I was sure yesterday but feel doubtful today."

Step 10: Maintain Humility Have an attitude of "I might not know," "Nothing is certain." The smartest people are those who know they don't know. People who doubt learn and grow more than those who are confident.

Impact

Positive Aspects

• Psychological comfort: Confirmation bias protects the ego. Confidence that you're right reduces anxiety and maintains self-esteem
• Quick decision-making: Considering all information makes decision-making difficult. Confirmation bias helps make quick decisions in a complex world
• Belief maintenance: Sometimes conviction is needed. If entrepreneurs hesitate thinking "will this work or not," they can't even start. Some unfounded conviction drives action

Negative Aspects

• Wrong decisions: Ignoring contrary evidence leads to big mistakes. It can lead to investment failures, business failures, relationship destruction
• Hinders learning and growth: Not accepting new information prevents development. The attitude "I already know everything" blocks learning
• Amplifies conflict: When everyone only confirms their own beliefs, dialogue becomes impossible. It's a major cause of political polarization and social conflict
• Irrational behavior: Continuing irrational behavior by ignoring clear evidence. Continuing harmful health habits or losing investments
• Trap of expertise: Experts can have stronger confirmation bias in their field. They cling to old knowledge and reject new paradigms

FAQ

Q: What's the difference between confirmation bias and stubbornness? A: They seem similar but are subtly different. Stubbornness is consciously deciding "I won't change my mind." Confirmation bias is unconsciously seeing only information that matches your beliefs. Stubborn people know they're stubborn, but people with confirmation bias think they're objective. The latter is actually more dangerous because they don't recognize their bias.

Q: Are there people without confirmation bias? A: No, everyone has it. Psychologists, scientists, judges all have confirmation bias. There are just differences in degree. People trained in critical thinking recognize and try to control confirmation bias. But it can't be completely eliminated. It's the brain's basic operating mode. What's important isn't thinking "I don't have confirmation bias," but thinking "I also have confirmation bias, so I should be careful."

Q: Does social media make confirmation bias worse? A: Absolutely. Social media algorithms show you more content you like. If you like conservative posts, only conservative posts appear; if you like progressive posts, only progressive posts appear in your feed. This is called a "Filter Bubble." You only meet people with the same thoughts and block opposing views, so you mistakenly think "everyone thinks like me." In reality, there are many opposing views. This is a major cause of intensifying political polarization. Solution? Intentionally follow accounts with different perspectives or search for information directly rather than relying on algorithmic recommendations.

Q: Do scientists also have confirmation bias? A: Yes, they do. That's why science has systems to prevent confirmation bias. For example, "Peer Review" means other scientists critically examine research. "Double-blind tests" prevent bias by ensuring neither researchers nor subjects know who's in the experimental group. "Falsifiability" asks "is there a way to prove it's wrong?" Individual scientists have confirmation bias, but the scientific community's system checks it. Of course, it's not perfect. Famous scientists' theories survive longer, and new theories contrary to existing paradigms sometimes take decades to be accepted.

Q: Can confirmation bias be used to persuade others? A: It's ethically problematic, but it's widely used in marketing and politics. The method is simple: start with what the other person already believes. "You value health, right? Then this product..." You confirm their existing belief and then connect your message to it. Targeted advertising works the same way. People interested in the environment get "eco-friendly" products, and budget-conscious people get "value" products. It uses each person's confirmation bias. But using it manipulatively loses trust. It's better to use it honestly for long-term benefits.

Q: How should you deal with someone with strong confirmation bias? A: Direct contradiction is counterproductive. They become defensive and more confident. Instead, try this: 1) Find common ground - Start with "I agree on that part." 2) Ask questions - Make them think with questions like "How would you explain this case?" 3) Share your experience - Naturally say "I thought that way too, but my thinking changed after this experience." 4) Give time - They won't change in one conversation. Plant the seed and give time. 5) Know when to give up - You can't change everyone. Some topics are too emotional for dialogue. Then it's okay to accept disagreement. "We think differently on this. But let's stay friends."