That would help explain the socialist tendencies of their descendants.
Tribe and clan has always been around and important. Hard to take down megafauna as one by yourself, hard to further the species without many wives and DNA diversity. It takes many with support in the resupply of lithics and meat or seasonal gathering and processing. But... Not that clan is not important, but there is a limit to how many a certain local environment can practically sustain. We have of course reached that limit my friend... :)