One of the greatest barriers to genuine human communication is the projection of stereotypes. If you (no not you Emmline - just a general comment here) notice someone behaving in, what appears to you to be, stereotypical manner and you treat that person according to the perceived stereotype, you end up reinforcing or entrenching the stereotype.
Stereotypes do contain an impression of truth, I cannot deny that - an imprint accessed by a needle, or more lately, laser penetration. Hardly the stuff of sweetness and nurture …