A lot of men do grow up beating the shit out of each other for basically no reason. I grew up in a family of all brothers. One of my older brothers has two girls and a boy now, and the level of sheer physical violence we were allowed to get up to on each other over stupid kid shit because "boys will be boys" (we'd get into full-on wrestling matches with punches and kicks and generally only be called out if anyone went for the face) versus how quickly my nephew/nieces get called out by their grandparents and parents for like, pulling on something they want aggressively, really served as a "oh shit this is why society is like this" check for me.