“Although beliefs in MHGs do coevolve with political complexity, [the] beliefs follow rather than drive political complexity,” the researchers say. For BSPs, however, the beliefs seem to help political complexity to emerge, although by no means guarantee it.

“I think the ordering of events these authors prefer is what one expects from first principles,” says evolutionary biologist Mark Pagel of the University of Reading, UK. He says that societies became more politically complex as networks of trade and reputation emerged, and that the key to this process was language, not religion.

So what are MHGs for? “They are tools of control used by purveyors of religion to cement their grip on power,” says Pagel. “As soon as you have a large society generating lots of goods and services, this wealth can be put to use by someone who can grab the reins of power. The most immediate way to do this is to align yourself with a supreme deity and then make lists of things people can and cannot do, and these become ‘morals’ when applied to our social behaviour.”

Anthropologist Hervey Peoples at the University of Cambridge, UK, says that there is good evidence that, even if MHGs do not drive political and social complexity, they can affect and stabilize it. “This study is impressive and innovative, but may be hard to generalize,” she adds.

Norenzayan agrees. “In Austronesia, social and political complexity has been limited”, he says. “There have been cases of chiefdoms but there has not been a single state-level society. So it’s not all that surprising that big moralizing gods don’t play a central role.” He argues that such gods did co-evolve with the very large, state-level societies typically found in Eurasia. The “big Gods” idea was never supposed to hold true everywhere, he says.

Complex Societies Evolved without Belief in All-Powerful Deity – Scientific American.