Conjunction Fallacy
Version 1.0.0 · Updated 2026-07-30
CORE DEFINITION
People tend to believe that the probability of 'A and B' occurring is greater than the probability of 'A' alone, which is mathematically impossible. For example, people think that 'Linda is a feminist bank teller' is more likely than 'Linda is a bank teller' because the former matches descriptive details more closely.
SCAFFOLDING EFFECT
Reduce cognitive load
The deceptiveness of details. The more specific and detailed a story is, the more credible it sounds, but in reality, the lower the probability of occurrence. When making predictions, be wary of scripts full of vivid details; they are a slide into fallacy.
Anchor fast decisions
According to probability axioms, A∩B is necessarily contained in A, so P(A∩B) ≤ P(A). But the human brain uses 'representativeness heuristic' instead of calculation: descriptions that fit existing stereotypes (Linda seems like an active feminist) appear more 'likely', ignoring set relationships. Vivid details provide availability anchors, making compound events feel more vivid than their superset, thus overriding logic.
MINIMUM ACTION
In progress 0/1Practice this model in one real situation:
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Source support: Explicit
- zh.wikipedia.orghttps://zh.wikipedia.org/wiki/%E5%90%88%E5%8F%96%E8%B0%AC%E8%AF%AFverified
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