Are physical traits heritable? Is temperament heritable? Is intelligence heritable? How are traits inherited? What part of basic biology allows dismissing physiognomy? Obviously nurture plays a role a large role, but to say predispositions to certain behaviors aren't passed down on the same chromosomes that also control physical characteristics is retarded. If you go step by step people usually don't have an actual response. Just make sure to emphasize individual agency and people having choices in what they do.