Then somebody claimed, "stereotypes typically have their basis in some reality."
I don't know about you, but I have seen that excuse used countless times to defend stereotypes.
A response to this was: "Please do read this or take a social psychology course. Stereotypes have a basis in human psychological folly. Anything from observer's bias, to illusory correlation, to socialization, to simple bigotry is much more likely the cause of a stereotype than "reality" as you put it. I can't believe how much defensiveness there is over stereotypes."
I think it's funny how a psychology course is needed for some people to question stereotypes, but the main points are summed up here:
"Different disciplines give different accounts of how stereotypes develop: Psychologists may focus on an individual's experience with groups, patterns of communication about those groups, and intergroup conflict. As for sociologists, they may focus on the relations among different groups in a social structure. They suggest that stereotypes are the result of conflict, poor parenting, and inadequate mental and emotional development. Once stereotypes have formed, there are two main factors that explain their persistence. First, the cognitive effects of schematic processing (see schema) make it so that when a member of a group behaves as we expect, the behavior confirms and even strengthens existing stereotypes. Second, the affective or emotional aspects of prejudice render logical arguments against stereotypes ineffective in countering the power of emotional responses."
Example: a person sees a few pissed off short men, and that confirms the Napoleon Complex, while ignoring all the tall men who behave in the same manner. This is how stereotypes are spread by those who wish to simplify their worldview. It's all a matter of convenience to justify narrow-mindedness.