Actually it is human nature. Males are warriors. And worse is alpha males want to control stuff.
Maybe some, but not all people. Propeties that are bad should reduce in Darvin cycles.
The idea that it is TV and Hollywood is nuts. For American Plains Indians there was no Hollywood in 1800 and yet they were always at war with each other. In fact some studies show that the death rates have declined in man even with the advent of Hollywood. It may be that vicarious war is a better outlet for those human impulses than real wars.
You think that violence looking and child violent grow ambient don't give any effect? Maybe hollywood had make some brainwash? And I don't say that hollywood is only responsible. It make some good things too, but many films are violent and make criminals to heroes, people killing soldiers to heros etc.
It is maybe good for army recruiting, but is it right thing to rule others with power and guns? Is that what you want your children to learn?
Indians was so wild that slaves need to get from africa. Say enough? Azteck so bloodlust that kill own people etc. When man walk out from africa, ~50000 years ago man reach china, and ~40000 years ago they continued to america. You can look route from afrika to america and check what kind of people live during that route. Chinese, japanise, inuits, indians, aztecs. Cinese people quite peace lowing, japanize samurai etc. people continued north america and some continued to southamerica. Think what kind of leaders they have? What kind of people stayed and what kind of country it developed?
- lot of people stayed in china, only aggressive people and "alpha males" continued to north america, speread there for many diffrent indians start war together etc. South america continued only few strongest and cruelest leaders and they make bigger civilizations as north. But how they ruled? With blood.
Enviroment selection make things happens, but selectivity is big thing. If give power for "alpha mans" then it make wars until there is only one. Rule is blood.
If give room for peacefull rule then sience grow. As in greeck, arab, and later in europe. Religion is bad thing for sience, but it can keep civilization together especially in wild enviroment. Until religions collapse and sience start grow.
Kill rates don't prove anything. Medical care, better food, and laws, prisons effect much more who are killed. It is somekind of solution also to put 2% mens to prison. Is it good or effective is other question..
You can give boys dolls and girls truck toys at age 2 and by age 5 or 6 most boys want the trucks and most girls want the dolls. Humans are not blank slates.
Enviroment effect is heavy. Boy can interested other things too. Girl keeps doll, but that come genes and child production. And boy playing dolls exsist also.
We are not totally blank, but enviroment give 90% effect how things are later.
It is better to deal with human nature as it is than to pretend it is something it is not. Then you can design work arounds.
I think that grow time is most important. Enviroment gain or decrease genes effect.
Beter genes continue and bads go less. Process is extremely slow. (and I think it go backwards nowdays)