Is it hereditary when parent is a dumb jock who creates a ridiculously bad environment in terms of 'nurture' aspect? I am not sure you thought your argument fully through.
Yes, and science explicitly allows him to continue procreating where otherwise he would have not been able to (he was in an accident because he was stupid). It’s explicitly saying the darwinian winnowing of the weaker (dumber) members of the species has been interfered with.