religion and geography

Humanity has gone through thousands of different religions. Commonalities among them reflect the underlying needs and questions they answer, and differences among them reflect the conditions under which they were socially constructed. 

Here is a nice example of the latter:

Begin with religious beliefs. A striking proportion of rain forest dwellers are polytheistic, worshipping an array of spirits and gods. Polytheism is prevalent among tribes in the Amazon basin (the Sherenti, Mundurucu, and Tapirape) and in the rain forests of Africa (the Ndorobo), New Guinea (the Keraki and Ulawans), and Southeast Asia (the Iban of Borneo and the Mnong Gar and Lolo of Vietnam). But desert dwellers—the bedouin of Arabia, the Berbers of the western Sahara, the !Kung of the Kalahari Desert, the Nuer and Turkana of the Kenyan/Sudanese desert—are usually monotheistic. Of course, despite allegiances to a single deity, other supernatural beings may be involved, like angels and djinns and Satan. But the hierarchy is notable, with minor deities subservient to the Omnipotent One. This division makes ecological sense. Deserts teach large, singular lessons, like how tough, spare, and withholding the environment is; the world is reduced to simple, desiccated, furnace-blasted basics. Then picture rain forest people amid an abundance of edible plants and medicinal herbs, able to identify more species of ants on a single tree than one would find in all the British Isles. Letting a thousand deities bloom in this sort of setting must seem natural. Moreover, those rain forest dwellers that are monotheistic are much less likely to believe that their god sticks his or her nose into other people’s business by controlling the weather, prompting illness, or the like. In contrast, the desert seems to breed fatalism, a belief in an interventionist god with its own capricious plans.

Another major difference was brought to light by Melvin Ember. Desert societies, with their far-flung members tending goats and camels, are classic spawning grounds for warrior classes and the accessories of militarism: military trophies as stepping stones to societal status, death in battle as a guarantee of a glorious afterlife, slavery. And these cultures are more likely to be stratified, with centralized authority. A cosmology in which an omnipotent god dominates a host of minor deities finds a natural parallel in a rigid earthly hierarchy.

Robert Sapolsky - writing about a seminal research article of Malvin Ember