I know it happens, but I struggle to get my head around it, and just don't get how anyone can treat someone else like that, it makes my blood boil.
They (the males of our species, that is) behave that way because other males (their friends, their relatives, their colleagues) don’t correct them. They don’t because, just like the perpetrator, they feel it’s the ‘manly’ way to behave! Testosterone overload, in other words!
Oh, the perpetrator wouldn’t want his mother, his sister, his wife, his girlfriend or, indeed, any female associated with him, treated badly.
He’d think that the macho way to deal with that, would be to physically ‘lash out’ to show what a ‘big man’ he is, how tough he is, how strong he is, etc.
He would think nothing of behaving in a vile and, or, vulgar manner if the female was on her own, inebriated - (great opportunity for all sorts of ‘macho’ behaviour there!).
These ‘men’ behave like that because they haven’t had a good example in their miserable little lives. They haven’t had a grown up male teaching them, from a young impressionable age, that boys don’t hit girls’. I can remember at primary school, one of my teachers telling a little boy in my class, that “boys don’t hit girls”.
Parents these days don’t give their children sound advice (or, indeed, ANY advice!) on how to behave, how to conduct oneself. They can’t even be bothered to properly toilet train them, sending them to school in nappies - for teacher to deal with it!