A mental shortcut where people judge probability based on how similar something is to their mental prototype or stereotype, often ignoring base rates and other relevant statistical information. This leads to systematic errors in probability estimation.
Coined by Kahneman and Tversky in the 1970s during their research on judgment and decision-making. The term emphasizes how people assess likelihood based on how 'representative' or typical something appears to be of a particular category, rather than using statistical reasoning.
The representativeness heuristic makes you a terrible statistician but a decent pattern recognizer! It's why people think a sequence like H-T-H-T-T-H looks more 'random' than H-H-H-T-T-T, even though both are equally likely - your brain has a stereotype of what randomness should look like.
Complete word intelligence in one call. Free tier — 50 lookups/day.