Examples of confirmation bias are found in news reports, academic research and interpersonal relations. For example, a journalist demonstrates confirmation bias when she interviews only those experts who support her story's angle. A student writing a research paper illustrates confirmation bias when he only references resources in line with his thesis, and he excludes any contradictory evidence. In personal relationships, people tend to see those aspects of a loved one's personality that support preconceptions, such as when a mother cannot see any flaws in her child's behavior or a lover is blind to a partner's faults.
Confirmation bias is the tendency for people to selectively search for and consider information that confirms already held beliefs. People also tend to reject evidence that contradicts their opinions.
Confirmation bias manifests in three ways. One is the biased search for information, where someone favors evidence that is supportive regardless of its validity. Another manifestation of confirmation bias appears in biased interpretation of evidence according to whether it agrees or disagrees with existing hypotheses held. A third form of confirmation bias is seen in biased memory when someone selectively recalls information that reinforces his or her expectations.
Confirmation bias is especially prevalent with established beliefs and emotionally significant issues.
Confirmation bias is also referred to as confirmatory bias or myside bias.