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Cognitive dissonance theory explains human behavior by positing that people have a bias to seek consonance between their expectations and reality. According to Festinger, people engage in a process he termed "dissonance reduction", which can be achieved in one of three ways: lowering the importance of one of the discordant factors, adding consonant elements, or changing one of the dissonant factors.This bias sheds light on otherwise puzzling, irrational, and even destructive behavior.
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A key assumption is that people want their expectations to meet reality, creating a sense of equilibrium.Likewise, another assumption is that a person will avoid situations or information sources that give rise to feelings of uneasiness, or dissonance.

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