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The Value of Probabilistic Thinking: Spies, Crime, and Lightning Strikes

Farnam Street (Shane Parrish) · 2018

"Good decisions under uncertainty require three specific probabilistic skills: Bayesian updating (weighing new evidence against prior knowledge), recognizing fat-tailed distributions (where extreme outliers are far more common than a normal bell curve implies), and correcting for asymmetric estimation errors (like investors who systematically overestimate their own returns)."

The idea

Bell-curve ('normal') distributions have predictable, bounded extremes (you'll never meet a man ten times the height of average); fat-tailed distributions (wealth, terrorism risk, market crashes) have no such natural cap, meaning rare extreme events are far more likely and far more consequential than bell-curve intuition suggests — so comparing a fat-tailed risk (terrorism) to a bell-curve risk (slipping on stairs) using only recent-year death counts, as some commentators do, misunderstands which kind of distribution you're actually in.

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Up NextSuggested: Continues the theme of Mental Models

Descriptions Aren't Prescriptions

"A representation of reality (a map, a grammar book, a law, a mental model) can be read either descriptively (this is how things currently are) or prescriptively (this is how things must be) — confusing the two, especially when the description becomes outdated, causes real, avoidable problems."

Farnam Street (Shane Parrish) · EssayContinue→
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