No, cavemen were very egalitarian. This is because back then, you couldn't hoard much of anything - food spoils quickly, sex requires your partner to like you, and personal possessions were things like tools or the odd bit of clothing. It was when wealth could be preserved, such as livestock, stored grain, jewelry, and eventually coinage, that wealth became an hereditary thing.

This is why a future economic system has to be designed to prevent the excessive hoarding of wealth. Not too little, nor too much. Humans weren't evolved to be free of consequence, especially from each other.