Chimpanzees have a strictly hierarchical society, and they all know their place in it. Our other ape cousins are also pretty hierarchical. Mobile human hunter-gatherer societies, the prototypical human societies that nearly all of our ancestors probably lived in for something like 40,000 years, and some modern and near modern hunter-gatherers still live in, are not like that. Instead, there is a high degree equality among all (adult male) hunters, and egalitarianism is strictly enforced, by shaming, ostracizing, expulsion, or extreme cases, murder of those who try to exploit or lord it over others.
It's likely that this egalitarian focus made possible the high degree of human cooperation which has enabled our extraordinary developments in art, technology, and civilization. In particular, humans display the ability to cooperate outside of purely familial groups.
Boehm, Christopher (2012-05-01). Moral Origins: The Evolution of Virtue, Altruism, and Shame (p. 30). Basic Books. Kindle Edition.