Cognitive Dissonance
Cognitive Dissonance is the mental discomfort experienced when holding two or more contradictory beliefs, values, or attitudes simultaneously, or when behavior conflicts with existing beliefs. First theorized by Leon Festinger in 1957, this mental model explains why people rationalize bad decisions, why cult members double down after failed prophecies, and why smokers continue despite knowing the health risks. Understanding Cognitive Dissonance allows decision-makers to recognize when they're rationalizing rather than reasoning, design more persuasive communications, and build organizations that reward intellectual honesty over comfort.