Conjunction Fallacy

We believe a specific, detailed scenario is more probable than a general one — even though this is a logical impossibility. Narrative plausibility overrides mathematical probability.

• In Kahneman's 'Linda' experiment: told Linda is a feminist philosophy graduate, people rate 'Linda is a feminist bank teller' as more probable than 'Linda is a bank teller' — which is logically impossible.
• A detailed scenario of how a stock market crash will unfold feels more convincing than the simple statement 'the market will decline.'
• Insurance buyers purchase specific terrorism coverage more readily than general accident coverage — even though the general policy covers the specific threat.