Confirmation bias, also called confirmatory bias or myside bias, is the tendency to search for, interpret, favor, and recall information in a way that confirms one's preexisting beliefs or hypotheses. It is a type of cognitive bias, which becomes a systematic error of inductive reasoning and a fallacy when people conclude that this proves that their beliefs are correct.
People display this bias when they gather or remember information selectively, or when they interpret it in a biased way. The effect is stronger for emotionally charged issues and for deeply entrenched beliefs. Confirmation biases contribute to overconfidence in personal beliefs and can maintain or strengthen beliefs in the face of contrary evidence.
The confirmation bias is an important reason for why people continue to believe false, but emotional beliefs, even if there is overwhelming evidence against their factual correctness.