Optimism Bias

Ask people their odds — of divorce, of business failure, of missing the deadline — and they reliably answer below the true average. Everyone believes the statistics apply to others. We are, as a species, professionally hopeful about ourselves.

The bias has honest uses. It gets the plane boarded, the marriage attempted, the venture launched. A species with accurate odds might never leave the cave. Hope is the fuel of every beginning, and the fuel is systematically overfilled.

But the overfill has a ledger. The budget that assumed the best case. The schedule with no slack. The health ignored because "I feel fine." Optimism builds the plan on the mountain's good side and is surprised by weather.

The mature stance has a name worth keeping: hopeful in spirit, pessimistic in the spreadsheet. Dream the best case — it supplies the courage — then plan the likely case and insure the worst. The optimist starts the journey. Only the prepared optimist finishes it.