I'm guessing you didn't click the link, to high on your soap box, so here
Confirmation bias, also called
confirmatory bias or
myside bias,
[Note 1] is the tendency to search for, interpret, favor, and recall information in a way that confirms one's preexisting beliefs or hypotheses.
[1] It is a type of
cognitive bias and a systematic error of
inductive reasoning. 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 bias is a variation of the more general tendency of
apophenia.
People also tend to interpret ambiguous evidence as supporting their existing position. Biased search, interpretation and memory have been invoked to explain
attitude polarization (when a disagreement becomes more extreme even though the different parties are exposed to the same evidence),
belief perseverance (when beliefs persist after the evidence for them is shown to be false), the irrational primacy effect (a greater reliance on information encountered early in a series) and
illusory correlation (when people falsely perceive an association between two events or situations).
A series of
psychological experiments in the 1960s suggested that people are biased toward confirming their existing beliefs. Later work re-interpreted these results as a tendency to test ideas in a one-sided way, focusing on one possibility and ignoring alternatives. In certain situations, this tendency can bias people's conclusions. Explanations for the observed biases include
wishful thinking and the limited human capacity to process information. Another explanation is that people show confirmation bias because they are weighing up the costs of being wrong, rather than investigating in a neutral, scientific way.
Confirmation biases contribute to
overconfidence in personal beliefs and can maintain or strengthen beliefs in the face of contrary evidence. Poor
decisions due to these biases have been found in political and organizational contexts.
[2][3]