Conjunction fallacy
Also called: Detail makes it seem likelier
Thinking two things together are more likely than one of them alone.
How to spot it
Has an extra detail made a story sound more likely?
Example
“She's likely a librarian who also plays the flute, more than just a librarian.”
How to answer it
Adding details can only make something less likely, never more.
Related
- Base rate fallacy: Judging a probability from a striking detail while ignoring how common the thing is overall.
- Hasty generalization: Drawing a broad conclusion from too few or unrepresentative examples.