Learning to fight is a difficult skill to accomplish and its complicated by some social and emotional factors.
It’s an activity, at least for men, closely linked to the concept of “manliness.”
Most people have gone through the gauntlet of childhood in which there is at least some threat of violence. By the time most people reach 20, they have felt threatened with violence, whether in school or on the playground or in a bar or on the streets.
While women definitely have it worse in the “being threatened by the world” department, by and large, they don’t typically have the pressure men feel to be perceived as competent fighters. It is an integral part of being “macho,” or “manly,” or really even competent as a boyfriend, husband, and father. Can you protect your loved ones against the world?
As a result of these pressures, many men feel compelled to be (or pretend to be) experts in violence. Fighting is a big topic of conversation in grades schools and high schools and colleges and in the military dorms. Few people are highly skilled fighters (as it takes a lot of dedication and training), so there is a lot of posturing going on.
I think of it as like “protective coloration” in the animal kingdom (the other animals).
Biological weapons which make an animal dangerous always have costs. To make and maintain claws, teeth, poison, muscles, and so on costs a lot of energy. So some animals evolved more energy-efficient ways to accomplish the same security goals. They pretend to be dangerous. Since having a bad run in with a dangerous creature is so risky (death, injury), other creatures evolve flinch and flight responses to dangerous creatures like poisonous snakes and spiders.
You ever have one of those involuntary jump responses to what you thought was a snake? Or actually was a spider? These reactions are wired into you.
Many animals have developed instinctive fear reactions to dangerous animals (bears, wolves, big cats, snakes, spiders).
So other creatures evolved a way to ride the coattails of this effect. They evolved to mimic the look of their more legitimately dangerous cousins. There are snakes which are not poisonous which are colored like their poisonous cousins.
There are fish, like the Puffer Fish, which blow themselves up with air to seem bigger and more dangerous.
Men (and especially teenagers) puff themselves up with words and they mimic the dress, habits, and attitudes of other men who are legitimately dangerous.
You see this most clearly in the way teenagers often start smoking and swearing to seem grown up. They may also dress and adopt the body language of people they perceive as feared, such as criminals. In my father’s day, kids would get a DA haircut and wear t-shirts with the sleeves rolled up and jeans and boots. By my high school years, it was a similar “Rock and Roll” look, only now the jeans were well-worn and sometimes torn at the knees and the t-shirts bore the logos of “edgy” bands like the Ramones and AC/DC.