Optimism Bias
- “why do I think it won't happen to me”
- “optimism bias explained”
- “why projects always run over”
- “unrealistic optimism research”
01 · Side by side
Side by side
Comparison sheet
| Aspect | Optimism bias | Optimism |
|---|---|---|
| Is | A judgment error | A temperament |
| Measurable as | Impossible group maths | Self-report |
| About | Comparative risk | General outlook |
| Universal | Not quite (79%) | No |
02 · Which one you meant
Which one did you mean?
In shortReaders who land here meaning Optimism Bias rather than Optimism are usually searching for phrases like “why do I think it won't happen to me”, “optimism bias explained”, “why projects always run over”.
03 · The mix-up
Where the confusion comes from
The mix-up“Optimism bias is just being an optimistic person.”
What's true
It's a measurable error in probability judgment, not a temperament. The signature is structural: a whole group cannot all be at below-average risk of divorce, yet Weinstein's 258 students collectively claimed exactly that.
04 · Read either one