I think it started off as authority given to charismatics leaders from a god. Then kings represented god and held his authority. It gets tricky when we get to democracy. I think in the West we still thought of human authority as somehow infused with the authority that came down through our Judeo-Christian culture. Now I think we realise they are all hard-necked impostors whose incompetency and immorality is getting clearer day by day.

The explanation is a long one. It might be worth you joining the anthro group. However basically, once we had the job of feeding everyone sorted humans were able to release a group of probably highly sensitive people to 'study' their world. Those people watched the world and made connections that may have initially been coincidencies but later became established facts, 'everytime we sacrifice a baby it rains'. 'The gods must like baby meat!' Other members of the group were physically stronger, luckier, more charismatic and consequently people listened to them. When these two sets of power brokers got together, ther voices were unchallenged. Its telling that in the Hebrew bible (and other ancient texts) only the priest class could wear gold and fancy clothes and have the best bits of sacrficed animals.