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Base-rate neglect

Underweighting background probabilities in favor of case-specific details.

Published 04 August 2026Updated 04 August 2026

Base-rate neglect occurs when a vivid description or matching story overwhelms information about how common an outcome is in the relevant population. Begin with the prior rate, then update it in proportion to the reliability of the new evidence.

Sources

Judgment under Uncertainty: Heuristics and Biases

Science / 1974 / Paper

Classic heuristics and biases paper.