- The conjunction fallacy is the mistaken belief that specific conditions are more probable than a single general one.
- Adding conditions can only reduce or maintain probability, never increase it.
- This is a well-known cognitive bias studied in rationality and decision-making.
- Probability can be subjective depending on the information available to the observer.
- A secretly observed coin flip is 100% certain for the observer but 50% for everyone else.
- Knowledge asymmetry changes the probability assessment for different people.