I should first emphasize that while Stewart-Williams and I share the view of the evolutionary roots of some male aggression, we both agree that males can also be socialized into being more aggressive by being expected to conform to stereotypes of “masculinity” (remember the car race in Rebel Without a Cause?); and that even if males are more aggressive than females because of natural selection, that doesn’t mean that you can’t make them less aggressive—also by socialization. Any geneticist knows that, for nearly all traits, heredity is not destiny, and the environment can make a big difference.
Nevertheless, the SJW view of differences between men and women’s behavior is that all of those differences are due entirely to socialization, with no moiety due to genetics and evolution. That is an ideological stand that, in view of the substantial morphological differences between men and women, is pretty insupportable. And that view comes from the fear that if we do find evolution-based differences, it will lead to discrimination—usually against women. My own view is that any genetic differences we see cannot support any moral or legal inequality between the sexes, which is a philosophical position that shouldn’t depend on biology. (If it did, equality would change as our knowledge of biology changed.)