Today’s most popular religions have one thing in common: gods or supernatural laws (such as karma) that dictate moral behavior and punish transgressions. Act morally and these supernatural forces will reward you; break the rules and you’ll be punished.
But moralizing gods seem to be quite rare in human history. Researchers know from ethnographies that the gods of hunter-gatherer societies, for example, don’t much concern themselves with humans, much less their moral behavior. (Many of them focus on nature instead.) Now, a new study tests a popular hypothesis about why moralizing gods eventually took over.