Comment by goatlover

Tribes still have leaders, elders, priests and what not. Similar to how apes have alpha males and females with a pecking order. Members of the group have a certain status in the hierarchy, even if resource access is mostly egalitarian. But what happens when you start having a bunch of tribes living nearby on a regular basis? Then you have emergent leadership across tribes. It could be by force or democracy or by whatever means. But human civilization is an emergent phenomenon once you have dense enough populations regularly living in a region.