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KahnemanBlack SwanBias

Overconfidence

Сверхуверенность · Чрезмерная уверенность

We are systematically more certain than we should be, especially about predictions and our own judgment.

Plain explanation

Confidence is generated by coherence, not accuracy. When the story in your head fits together, you feel sure - even if the story uses very little data. Experts are not immune; in many domains experts are MORE overconfident than novices because their stories are richer.

Why it matters

Overconfidence is the precondition for every other big mistake: planning fallacy, ignoring base rates, taking irreversible bets without guardrails. Calibration matters more than confidence.

Practical example

Asked to give a 90% confidence interval for an unfamiliar quantity, most people give one too narrow - and the true value lands outside it 40–50% of the time.

How to use
  1. 1Always state confidence as a number, then check yourself against actual outcomes over time.
  2. 2If you're 90% sure, ask: «what would the 10% world look like, and how would I notice I'm in it?»
Related tools
Original books

This part of the knowledge base is inspired by the book. Go to the Ukrainian edition to explore the concept in depth.

Source notes
  • · Методичка по Канеману - самоуверенность экспертов