Capitalism is well suitable to people at their current level, which is about developing a strong ego with intelligence and clear boundaries. Communism was appropriate in the past, when people had weak notion of self, is not appropriate now, and will be appropriate in the future when people want to give more and take less. "I think my nature was always one that strove to yield itself to the great whole of which it was such a small part - and by yielding itself, to draw back into it the sustenance of life." - a pretty good allegory on the essense of communism done right.
Given that all of recorded history has taken place in the last 10500 years, and that time has seen a huge diversity of social structures in civilizations across the globe, I think your pessimism is unfounded.
Yes, people are selfish. People also have a great capacity for cooperation and altruism, given sufficient cause to bind them together.
I rather hope that the impending collapse of the biosphere that sustains all life is just such a cause. Then again, we appear to be setting the world on fire at an ever greater pace.
