> Human society was beyond brutal then.

Was it really? There is very little evidence of Paleolithic warfare (especially evidence that is direct evidence of war as opposed to perhaps being capital punishment or the like). It's not until you get sedentary populations that you find clear evidence of warfare, and even then, there's still a great many settlements in early periods whose layouts suggest that defense was not a concern.

Or, to put more bluntly, the evidence seems to indicate that it's rather late in the development of "civilization" [1] that warfare is invented.

[1] I'm framing this in the unilinear model of anthropology, which I don't believe in, because this is how popular anthropology treats it.

> "an incredibly fair system"

I almost fell out of my chair laughing.

Who suggests that any individual person walked "from Asia to North America"? Beringia itself was inhabited for millennia, even after the glaciers receded enough to allow walking south. Groups of humans could have moved a mile per year and covered the distance. (Although, it seems more likely that they moved back and forth much farther in a sort of Brownian fashion.) Also, many theorists suggest that much of the "fastest" migration was via watercraft along the west coast of the Americas.

America is something quite different from "the best country in the world". It would be more accurate (although still too simplistic) to say that we're the most successful "bad guys". Sure, there are other people who fight unnecessary wars of aggression for the commercial interests of privileged ruling-class assholes. It's just that we've fought so many, which have resulted in the violent deaths of so many millions. Eventually quantity has a quality of its own. It is interesting that one's response to this basically anthropological map would be "USA #1!?!"