[Retric]

There were no humans 500,000 years ago. "The term "human", in the context of human evolution, refers to the genus Homo," "The Homo genus diverged from the Australopithecines about 2 million years ago in Africa."

http://en.wikipedia.org/wiki/Human_evolution granted Homo sapiens are younger than that.

Nobody fought for "dominance" at any social institution I've been involved with. I recall doing this on several occasions in unscripted environments. I don't know if you are male, or if you spent much time unsupervised with groups of 8 - 20 other young men, but it's seemed really common.

This might also be more obvious to those who win these games. And there are edge cases. I recall having 12 people watching me play video games and when my mother asked me to share I offered and got a “we just want to watch” response. This seemed more like a completion to find the best followed by watching the master situation. But it was still odd and even though the observer never saw the dominance play it still happened and if I was less talented we would have kept sharing for longer.

I also recall being a member of a crowd watching the master at an arcade even if nobody watches game play videos. It's also customary to have the person who wins keep the table in pool or fighting games. This is normally less obvious than simply beatings ones chest, but watch how people walk around a body builder some time.