Confirmation bias: Belief trumps evidence
We tend to favour information that supports our pre-existing beliefs.
Have you ever held onto an incorrect belief about someone even though you were aware of evidence that contradicted your belief?
Do you only follow people on social media who share your political views?
Do you tend to jump to conclusions without checking whether these conclusions are correct?
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Confirmation bias is our tendency to search for and favour information that supports our pre-existing beliefs, and to ignore or devalue information that contradicts these beliefs.
For example, Person A believes the current levels of immigration are unsustainable, and only searches out and reads stories about the social, political and economic disadvantages of immigration. When he encounters information about the benefits of immigration, he interprets this information as unconvincing and ignores it. As a result, Person A continues to support his current beliefs.
Meanwhile, Person B believes the current levels of immigration are sustainable, and only searches out and reads stories about the social, political and economic benefits of immigration. When he encounters information about the disadvantages of immigration, he interprets this information as unconvincing and ignores it. As a result, Person B continues to support his current beliefs.
Confirmation bias is a largely automatic and unconscious cognitive bias, and works both for beliefs that we favour and ones that we don’t favour. The bias is most noticeable in the case of ingrained, ideological, or emotionally charged beliefs.
Our brain uses the confirmation bias as a shortcut to save mental energy. Humans have evolved to take the path of least resistance. Accepting information that supports our beliefs requires little mental energy. Evaluating evidence that contradicts our beliefs requires a lot of mental energy, so we prefer to ignore this evidence, interpret it in a way that supports our beliefs, or explain it away. Our brain also has a confirmation bias with regards to retrieval of memories: it retrieves supporting memories more than contradictory memories.
Due to biases such as WYSIATI (What You See Is All There Is), narrative fallacy, and social proof, many of our beliefs are not grounded in reality. Confirmation bias hinders the correction of these incorrect beliefs, and the more someone’s identity is attached to a belief, the stronger this bias becomes. This blind spot prevents us from seeing the full picture, causing our thinking to become narrow-minded and short-sighted. Consequently, incorrect beliefs can lead to poor decisions by distorting our view of reality.
Examples
On a societal level, confirmation bias increases the political polarisation. For example, when people strongly identify with a particular political party, they tend to focus on the shortcomings and mistakes of opposing party politicians while ignoring or downplaying their strengths and successes. This bias helps maintain stereotypes of cultural groups. When people encounter someone who defies a stereotype, they often rationalise why that person is an exception rather than revising the stereotype. Confirmation bias also supports the survival of conspiracy theories by making believers readily accept any evidence that supports their viewpoint while disregarding contradictory evidence. It can lead journalists to ignore evidence that challenges their story and scientists to avoid testing their hypotheses rigorously.
On an individual level, confirmation bias can negatively impact ourselves and our relationships. We often jump to conclusions about why others do what they do, and these conclusions are frequently incorrect. For example, if a friend doesn’t reply to your messages, you might quickly conclude that your friend wants to avoid you. Similarly, if a colleague doesn't greet you at the office, you might believe he dislikes you. Low self-esteem can reinforce these negative conclusions, leading to unhelpful beliefs that you are unlovable. The danger lies in not testing or investigating these beliefs, causing you to act as though they were true.
Vague or ambiguous beliefs allow individuals to selectively interpret information in a way that confirms these beliefs. For example, if a person believes in astrology and their horoscope predicts a good day, they may selectively notice positive events and attribute them to the accuracy of the horoscope. Conspiracy theorists often interpret ambiguous or circumstantial evidence as supporting their beliefs, ignoring other plausible explanations. Likewise, a believer who recovers after prayer may attribute the recovery to the power of prayer and divine intervention. Conversely, if the believer does not recover despite prayer, they may explain this as part of God's mysterious plan, allowing them to maintain their faith despite seemingly contradictory evidence.
Many business books are based on the belief that we can achieve success by applying particular strategies of successful people. However, the authors often focus only on confirming evidence, overlooking disconfirming evidence such as unsuccessful people who used these strategies or successful people who used other strategies. The same principle applies to many self-help books. For instance, an author might argue that practicing gratitude is the key to happiness, providing numerous examples of people who became happy through gratitude. However, such books typically does not include examples of unhappy people who practiced gratitude or happy people who did not practice gratitude.
Charles Darwin recognised the human tendency to favour information that confirms pre-existing beliefs and actively worked to mitigate its influence on his research. He diligently sought out and carefully considered evidence that challenged his views, recognising the importance of avoiding biased conclusions. Darwin meticulously documented observations that contradicted his theories, understanding that relying solely on supportive evidence could distort his findings. He remained open to revising his views based on new evidence and consistently made a deliberate effort to evaluate all evidence, whether supportive or contradictory, in his work. Over time, Darwin's theory of evolution by natural selection evolved as he encountered and integrated new data, continuously refining his ideas to better reflect the complexities of biological diversity and adaptation.
How can we reduce confirmation bias?
🛠️ Increase your awareness
The first step in reducing confirmation bias is to become more aware of it, especially with regard to unhelpful beliefs that have an adverse impact on your life. Observe yourself with curiosity as if you were a scientist or researcher, and try to be as objective and honest as possible. Don’t blame yourself for being biased, our brains have simply evolved this way.
After being exposed to information related to a belief you hold, for instance while reading an article or book, watching a documentary or listening to a podcast, ask yourself questions such as:
🤔 What parts supported my belief and how did I react to them?
🤔 What parts contradicted my belief and how did I react to them?
🤔 Did what I read, saw or heard confirm my belief? Why (not)?
After an experience in which your beliefs had an undesirable impact on that experience, ask yourself questions such as:
🤔 What belief of mine had a negative impact on the experience?
🤔 Have I ever tried to refute this belief? Why (not)?
🤔 Has this belief influenced my behaviour in an negative way? If so, why and how?
🛠️ Consciously look for contradictory facts
Get closer to the truth by not only looking for evidence that supports your beliefs, but by also consciously looking for evidence that contradicts what you believe. Instead of attempting to confirm your belief, you aim to falsify it. Do this especially for unhelpful beliefs that have an adverse impact on your life.
Think of yourself as a researcher trying to disprove a belief. For a brief period, consider that the opposite of your belief is true to open yourself up to contradictory evidence. Consciously look for facts that contradict your belief. For example, in your online searches, use terms like ‘hoax,’ ‘scam,’ or ‘false’ in conjunction with your belief. Expose yourself to information that differs from what you believe. Talk to people with different opinions and really try to understand their point of view.
When you are negatively affected by a belief you have about yourself or others, try to refute this belief. Ask the friend who hasn’t responded to your messages if he is trying to avoid you. Go to lunch with the colleague who didn’t greet you, to find out if he doesn’t like you. Boost your self-esteem by writing down facts that challenge your unhelpful beliefs, by acknowledging what you are good at, and by taking on challenges that are just outside your comfort zone.
Looking for contradictory evidence is basically about being curious and asking yourself the question:
🤔 How could I be wrong?
Like a judge or juror, carefully and impartially consider and weigh all evidence, both supporting and contradictory, to arrive at a balanced conclusion about your belief.
🛠️ Hold your beliefs lightly
Instead of taking our beliefs way too seriously, we should hold them lightly.
We are full of beliefs about ourselves and the world. It is important to realise that beliefs are just opinions. Opinions are not facts. They are mental constructs, not absolute truths. Many of our beliefs are based on very little information. We judge quickly, make unconscious assumptions, jump to conclusions without checking for truth, and ignore contradictory evidence when we encounter it. Because of our built-in negativity bias, we have many negatively biased beliefs about ourselves and the world.
The more seriously we take a belief, the harder it is to change it. A strong attachment to beliefs makes us hold on to ones that don’t serve us. When we attach ourselves only lightly to our beliefs, we are able to quickly get rid of ones that are no longer helpful. See your beliefs as ‘best guesses’ and ‘working theories’, not as the definitive truth. When they are no longer helpful, replace them with beliefs that serve you.
You can practice holding your beliefs lightly, by coming up with alternative explanations. For example, take the belief that the friend who hasn’t responded to your messages is trying to avoid you. Come up with three alternative explanations for his behaviour. For example, he does not respond because he is going through a difficult time, or because he is taking a break from social media, or because he has fallen madly in love and is neglecting all of his friends. Repeating this exercise regularly will increase your ability to look for different perspectives instead of sticking to one unhelpful belief.
References
Thinking, Fast and Slow, by Daniel Kahneman.
How to Know Everything, by Elke Wiss.
The Art of Thinking Clearly, Rolf Dobelli
5 Common Mental Errors That Sway You From Making Good Decisions, by James Clear
Confirmation Bias And the Power of Disconfirming Evidence, Farnam Street
What is Confirmation Bias?, WebMD, by Dayva Segal
Why do we favor our existing beliefs?, The Decision Lab
