The theory is that human beings until they learnt a form of communistic food gathering by males forced on them by female solidarity in the form of a sex strike. The sex strike was organised by synchronised menstruation in rhythm with lunar cycles. Full moon orgies were followed by dark moon menstruation and sex strike. This society helped human beings become human beings in the sense that food gathering for infants was greatly improved and language was invented. Primates who persisted in unbridled competition between males continued to be dominated by alpha males and the potential food gathering capabilities of other males for child rearing was unrealised. So the first human society was a communist society.
I cant remember all the evidence that supports this offhand, but things that have stuck in my mind are
1. The presence of a dragon myth in nearly all ancient societies. (The dragon being the symbol of the sex strike)
2. The fact that the mean female menstrual cycle is 28.25 days - exactly the same length as the lunar cycle.