Representativeness heuristic

What it is

Judging probability by how closely something resembles a typical example, while ignoring base rates and sample size.

Example Assuming a quiet, tidy person is more likely a librarian than a farmer, although there are far more farmers.

Base-rate neglect bias
Judging by resemblance leads us to ignore base rates.
False analogy fallacy
Analogies feel strong when something resembles something else, and judging by resemblance is the representativeness heuristic.
Gambler's fallacy fallacy
We expect short random sequences to look "random", so a streak seems to demand a correction.
Stereotyping bias
A stereotype is a representativeness judgment: a person resembles the group, so we assume the group's traits.
Conjunction fallacy fallacy
The conjunction fallacy arises because a detailed description is more representative, so it feels more probable.
Law of small numbers bias
We expect small samples to resemble the population, which is a representativeness error.
Undistributed middle fallacy
Believing two groups overlap because they share a trait is judging by resemblance.