Why are Americans drawn to the violence of football?

I teach a course on the intersection of sports and religion in North America, and I ask students whether there is something about American society that draws us to the violence of football. Why, for instance, despite the NFL’s best efforts, has American football not caught on elsewhere in the world, whereas by most metrics it is America’s most popular game? Sure, violence erupts from time to time in other sports — the consequence of a beanball pitch or an inadvertent collision in the heat of competition.