Confirmation Bias

Definition

Confirmation bias refers to processing information by looking for, or interpreting, information that is consistent with one's existing beliefs. This biased approach to decision making is largely unintentional and often results in ignoring inconsistent information. Existing beliefs can include one's expectations in a given situation and predictions about a particular outcome. People are especially likely to process information to support their own beliefs when the issue is highly important or self-relevant.

Background and History

The confirmation bias is one example of how humans sometimes process information in an illogical, biased manner. Many factors of which people are unaware can influence information processing. Philosophers note that humans have difficulty processing information in a rational, unbiased manner once they have developed an opinion about the issue. Humans are better able to rationally process information, giving equal weight to multiple viewpoints, if they are emotionally distant from the issue.

One explanation for why humans are susceptible to the confirmation bias is that it is an efficient way to process information. Humans are bombarded with information in the social world and cannot possibly take the time to carefully process each piece of information to form an unbiased conclusion. Human decision making and information processing is often biased because people are limited to interpreting information from their own viewpoint. People need to process information quickly to protect themselves from harm. It is adaptive to rely on instinctive, automatic reflexes that keep humans out of harm's way.

Another reason people show the confirmation bias is to protect their self-esteem. People like to feel good about themselves, and discovering that a belief that they highly value is incorrect makes people feel bad about themselves. Therefore, people will seek information [Page 163]that supports their existing beliefs. Another motive is accuracy. People want to feel that they are intelligent, and information that suggests one holds an inaccurate belief or made a poor decision suggests one is lacking intelligence.

Evidence

The confirmation bias is strong and widespread, occurring in several contexts. In the context of decision making, once an individual makes a decision, he or she will look for information that supports the decision. Information that conflicts with the decision may cause discomfort and is therefore ignored or given little consideration. People give special treatment to information that supports their personal beliefs. In studies examining the my-side bias, people were able to generate and remember more reasons supporting their side of a controversial issue than the opposing side. Only when a researcher directly asked people to generate arguments against their own beliefs were they able to do so. Often when people generate arguments against their beliefs, the arguments may be used selectively or even distorted or misremembered to ultimately support the existing belief. It is not that people are incapable of generating arguments that are counter to their beliefs; rather, people are not motivated to do so.

The confirmation bias also surfaces in people's tendency to look for positive instances. When seeking information to support their hypotheses or expectations, people tend to identify information that demonstrates a hypothesis to be true rather than look for information that the opposite view is false.

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