Commenting to go against the current replies who seem to deny obvious social and biological facts.
It's interesting that those types of comments usually come from the same people who would call animals "non-human animals" to show that humans are "just" another animal. Yet when you remind them Nature doesn't keep things that haven't found an equilibrium, they freak out...
Yes, any human group will naturally or forcefully get hierarchically ordered. "Anarchy" is just a fancy idea that doesn't pass reality's test. Or that won't be real "anarchy".