"Naturally on their own", you say?
It sounds like you consider humans outside of forces of nature, outside of evolution.
Are you a theist perhaps?
I'm trying to understand your position, because to me humans and human relationships and human societies and human actions seem (obviously) a part of nature. They're complex systems, yes, but there's nothing inorganic or unnatural or magical about them. The same rules of biology and physics apply as everywhere else.
And yes, coercing others to capture more resources for self seems a prototypical example of a (co-)evolutionary arms race.