What is Confirmation Bias?

Confirmation bias is our tendency to search for evidence that supports our opinions and beliefs.

It is one of the most insidious cognitive biases that exist in our daily lives. As Rolf Dobelli wrote,

“confirmation bias is the mother of all misconceptions.”

It is why two people can interpret ‘facts’ and come away with very different conclusions.

It is central to modern conflicts like identity politics, where groups of people tend to discount conflicting information without consideration.

Confirmation bias is a great danger; when we fall victim to it, we make large errors in judgment, and slow our learning.

It causes much of our societal inertia. It is particularly prevalent when evidence is complex or difficult to verify—areas like emotion and ideology.

We can't end confirmation bias; instead, we must get better at identifying situations where we are likely to fall victim, and plan accordingly.

The Purpose of Confirmation Bias

We can't live by weighing all evidence that comes our way against our old beliefs. It requires too much mental energy.

Our brain prefers to take shortcuts, so we dismiss information that conflicts with our beliefs. This saves us time and effort and allows us to make decisions fast.

Most of the time, this saves us headaches and extra thinking. 

It was a useful skill when the main decisions we made were about survival; we only needed to learn a few important rules (run from bears,  etc.), and we would be okay.

But in the modern world, it can cause us to make grave mistakes in judgment.

Where Does Confirmation Bias Occur?

In short: everywhere.

From The Art of Thinking Clearly:

“Whether you go through life believing that “people are inherently good” or “people are inherently bad,” you will find daily proof to support your case.”

In business:

“An executive team decides on a new strategy. The team celebrates any sign that the strategy is a success. Everywhere the executives look, they see plenty of confirming evidence, while indications to the contrary remain unseen or are quickly dismissed as “exceptions” or “special cases.” They have become blind to disconfirming evidence.”

Business and self-help books often fall victim to confirmation bias. 

Citing factors for success, they mislead us to believe they have unlocked a secret. 

The reality is that many more factors may have played a role. The mixup of correlation and causation often happens due to confirmation bias. We believe something to be true, and have a hard time evaluating the evidence, particularly in hindsight.

Confirmation bias plays a role in relationships too. If you believe your partner is amazing, you’ll focus on the qualities that reinforce that belief, and be happier as a result. 

But, if you believe the opposite, you will focus on their negative qualities, and be right, though much unhappier.

Confirmation bias exists throughout our lives.

Reducing Confirmation Bias

Understanding confirmation bias is the first step in reducing it.

Recognizing situations where you are a victim of confirmation bias is next. This part isn’t too difficult; assume always.

The tough part is to identify situations where confirmation bias is likely to have a detrimental effect. 

In business, hiring is a prime example. First impressions can be misleading and we tend to form opinions fast, based on factors that we don’t understand (see 'the halo effect').

To reduce the impact on hiring, you can do things like:

  • screening resumes without names or pictures, 
  • developing clear scoring matrices before interviews, and 
  • scoring as the interview progresses (instead of at the end).
  • These steps add opacity to the outcome and reduce the effect of confirmation bias.

In other words, you are reducing your ability to influence the outcome based on other factors (appearance, general 'feel', etc.).

Most of all, the key to reducing the impact of confirmation bias is to seek to be wrong:

“To fight against the confirmation bias, try writing down your beliefs—whether in terms of worldview, investments, marriage, health care, diet, career strategies—and set out to find disconfirming evidence.” - The Art of Thinking Clearly

If you believe a candidate is a good manager of others, try to find counter-examples. Can you find an employee at a previous job who wasn’t happy with this manager?

You can apply the same process to important opinions in your own life. What are your main beliefs? Can you find evidence that contradicts them? Why should or shouldn’t this change your belief?

Confirmation Bias Key Takeaways

Confirmation bias is one of the most prevalent errors in our thinking and judgment. 

Remember the following key points to reduce the negative impact confirmation bias has on your life:

  • Confirmation bias is our tendency to ignore contradictory evidence and emphasize information that matches our beliefs.
  • It exists in every aspect of our life, all the time. We do it to save ourselves mental energy and make decisions faster.

To counter confirmation bias, you must:

  • Recognize situations where it may have a significant negative impact,
  • Use processes to reduce your visibility of the outcome (add opacity),
  • Seek to disconfirm your beliefs in situations where you need a good decision.
“What the human being is best at doing is interpreting all new information so that their prior conclusions remain intact.” - Warren Buffett


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