There are a lot of unexamined assumptions here. Why would we assume that a prehistoric society had any particular system of economic interactions? It's not as if they wrote something we can read. In those cases in which tombs or whatever were left behind that we can examine, it typically seems that relatively rare "kings" were buried with all of the gold and other shiny rocks, and sometimes with some servants or wives for the afterlife who seem to have been ritualisticly killed for that purpose. Was that "capitalism"? Maybe!