There are a few in-world options to explain this. Although a stereotype isn't true generally, there can still be individuals who fit it the same way someone of another group could, who are then held up to justify the perception. Systemic oppression can also drive some to the stereotypical actions, raising a statistic. Someone could also lean into the perception if it bonds them with others or seems beneficial in another way; or, regular internalized prejudice. Or any combination of these.
- Val