Probability Blindness

Probability blindness is our chronic trouble thinking clearly about chance: we feel certain about uncertain things, overweight vivid risks, and ignore base rates. It’s a survival instinct — better to flee a hundred imagined lions than miss the one real one — running in an environment it was never built for.

I find it the most useful bias to name in product work, because data decisions are exactly where it bites. A confident stakeholder and a noisy chart are a combustible pair, and recognising the blindness is the first step to overruling it with the numbers.