A cognitive bias is any of a wide range of observer effects identified in cognitive science and social psychology including very basic statistical, social attribution, and memory errors that are common to all human beings.

Biases drastically skew the reliability of anecdotal and legal evidence.

Social biases, usually called attributional biases, affect our everyday social interactions.

And biases related to probability and decision making significantly affect the scientific method which is deliberately designed to minimize such bias from any one observer..

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