If you are a researcher looking for a topic, you naturally zero in on gaps of this kind. Well, now the research is being done, and the results coming in are unexpected. Far from being a loathsome aberration that ought to be purged from our behavior, it turns out that stereotypes are essential life tools, are accurate much more often than not, and that we do not use them as much as, from cold practical considerations, we should. Modestly, methodically, with batteries of experimental evidence, these researchers are demolishing most of what you thought you knew about stereotypes. People ascribe a stereotype to everybody in the subject group.
All English people have bad teeth.
In fact, these researchers were not able to locate anybody who believes that a stereotype is true of all members of the stereotyped group. Stereotypes are probabilistic tools, and even the most dull-witted human beings seem to know this. People who believe that Mexicans are lazy or that the French don't wash, understand perfectly well that there are losts of industrious Mexicans and fragrant Frenchmen. Stereotypes exaggerate group characteristics. No, they don't.