Women are called the civilizing influence on men. In other words, we’d all be happily hunting, gathering, and sowing our wild oats, were it not for our wives. Civilization would never have started in a world of single men. And this is probably true. Stable relationships with our spouses, and thus our offspring, caused men to adopt more predictable means of gather food; we began to farm rather than hunt. But this change in human behavior made us more violent, not less.
When your next meal comes from a particular bit of real estate, you learn to defend it. A hunter can get food anywhere, but a farmer can only get food from the field he planted. If others drive him off that land, he and his family will starve. To avoid this, he learns to defend that ground. To grow his family, he further learns to take land from others. Thus agriculturalists are more aggressive than “uncivilized” hunter/gatherers.
The moms of the world are what caused men to become warlike.
The first war was started when some cavewoman said “Hey, you big hairy Neanderthal, my boyfriend says he can take on your whole p*ssy tribe!”