A common heuristic with a statistical theme is the representativeness heuristic. We tend to think that someone or something likely belongs to a category if they have features typical of that category. While there is some truth to this, we overapply the rule and ignore two other critical pieces of information. First is the base rate—how common is that category? If the category is rare, then the probability of someone belonging to that category may still be low, even if they are typical for it. The second is predictive value—a feature may be typical of a category but not specific to it.
