Where do your beliefs and opinions come from? Most people like to think that their beliefs are the result of experience and objective analysis of the information they have available. However, the reality might be different (Plous, Scott (1993). The Psychology of Judgment and Decision Making. p. 233).

The confirmation bias is one of the most common biases in our everyday life. Like other biases, it hinders us to make conclusions on a rational basis and therefore can lead to poor or faulty choices.

The confirmation bias is the tendency to search for, favor, interpret and recall information in a way that confirms one’s beliefs or hypotheses, while giving disproportionately less consideration to alternative possibilities. This effect is even stronger for issues which are emotionally charged and for deeply entrenched beliefs. Confirmation biases lead to overconfidence in personal beliefs and can maintain or strengthen beliefs even in the face of evidence.

Less Wrong illustrates this bias with this example: “As an extreme example, imagine one hundred algorithms for stock market prediction placed in one hundred safety deposit boxes under a hundred different assumed names. Ten years later, to great fanfare, only one box, the one containing the most accurate post-facto results, is opened. There is no universally accepted and undeniable way to prove that any of the other 99 did or didn’t exist without a discipline that forces negative result reporting. Even a person who had filed away only one algorithm under their own name, once, would therefore be suspect.”

Confirmation biases are effects in information processing leading to biases in search for information, interpretation and memory.

Experiments have found that people tend to test hypothesis in a one sided way, by searching for evidence consistent with their current hypothesis. Rather than searching through all the relevant evidence, they phrase questions to receive an affirmative answer supporting their beliefs. As a consequence, their search for information is biased.

Confirmation biases are not limited to the collection of evidence. Even if two individuals have access to the same information, the way they interpret this information can be biased. Biases in belief interpretation are not affected by the level of intelligence.

People can gather and interpret the same evidence in a neutral manner, however, they will still remember it selectively to prove their existing beliefs. Information matching these expectations will be more easily recalled than information that does not match. (Hastie, Reid; Park, Bernadette (2005), “The Relationship Between Memory and Judgment Depends on Whether the Judgment Task is Memory-Based or On-Line”, in Hamilton, David L., Social cognition: key readings, New York: Psychology Press)

But is there any solution to counter this bias? Firstly, we need to know about it. With knowledge of confirmation biases one can scrutinize his or her thought process in order to attack contingent areas in decision making. Secondly, it is helpful to ask friends about topics in order to get a broader view. Thirdly, research suggests that “considering the opposite” can help to produce less biased evaluations (Sawin, Gregory (1988), “Consider the Opposite”, Et Cetera, p. 190). Using this approach, the decision maker should temporarily imagine that his or her initial belief was wrong in order to search for evidence supporting the opposing view. Lastly, even if the decision maker is still affected by this bias, he or she needs to know that the outcome of the decision making process might be flawed. Therefore, it is smart to split risks and not put everything on one single card.

Summing up, challenging your confirmation bias is definitely worth it!

FLORIAN ZINK

Florian Zink is in his second year at Bucerius Law School. The year before university, he completed his A-levels. He is passionate about fitness and enjoys debating with friends and fellow students. Quite recently, he learned about Rational Thinking and from that moment it became something he wants to learn more about and get people involved in.

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