Darwin noted that a belief in “all-pervading spiritual agencies” is well-nigh universal among human populations. There are two current theories to explain the origins and persistence of religious belief, John Derbyshire reminds us:
One says that religion is an accidental by-product of our extremely complicated cognitive equipment. Being able to tell when an object is possessed of volitional agency (tigers, enemies) is so vital to individual survival that the ability “slops over,” attributing agency where there is none. A tree, the sun, or a statue can then be believed to have volition and power. Yale psychologist Paul Bloom popularized this point of view in a 2005 Atlantic Monthly article (“Is God an Accident?”). Anthropologists Scott Atran and Pascal Boyer have presented it at book length.The other theory is that religion is adaptive. That is, on net, human beings who have religious instincts propagate their genes more successfully than those who don’t. The best-known exponent of this point of view is biologist David Sloan Wilson, whose 2002 book Darwin’s Cathedral laid out the adaptionist case for a general reader.
In The Faith Instinct, Nicholas Wade explores the adaptive approach — survival of the most pious:
The first task here is to try tracing developments through long history — through, that is, the 50 or 60 millennia since Homo sap. emerged from East Africa to populate the world. With lactose tolerance, the tracing is easy: Before cattle herding came up, there was none; afterwards, it soon appeared in the relevant populations, the culture at work to change the genetics.With religion, things are much more complicated. There have been distinctive styles of worship in different periods of long history. Before the agricultural revolution of 8000 B.C., all human beings lived in small hunter-gatherer groups. Fragments of this lifestyle survived late enough that we can say confident things about it. It was very egalitarian — “fiercely” so, says Wade. (“Primitive communism,” was Karl Marx’s term.) This is a puzzle by itself, as our closest relatives, the chimps, live in hierarchical societies. Since chimp genes are known to have changed much less than ours, presumably the common chimp-human ancestor was hierarchically inclined.
So how did we get egalitarian? Wade suggests the invention of weapons (recall one meaning of the word “equalizer”), together with increased intelligence: “the cognitive ability of the weak to form coalitions against tyrannical leaders.” But then, without the authority of alpha males, how was order to be kept in the egalitarian hunter-gatherer band? How were deviants and freeloaders to be deterred? Religious belief, Wade argues, offered an answer. Supernatural agents, perhaps first suggested by dreams, could punish and reward.
The style of worship among hunter-gatherers was likewise egalitarian, with communal dancing and chanting a major component. These ceremonies sometimes lasted for weeks. Participants worked themselves up into trance states, interpreted as communication with, or possession by, supernatural agents. Some cultures used hallucinogens as a shortcut, since, as Wade notes, “dancing for hours on end was an arduous way to gain access to the supernatural.”
When settled agricultural life began, around 8000 B.C., religion changed to match the new circumstances. Ceremonies were pegged to key agricultural events — planting, harvesting — and the need for social hierarchy threw up specialist classes of priests, probably in cultural line of descent from the shamans of some hunter-gatherer societies — individuals with special talent at attaining the trance state. Religion was still tribal and polytheistic, though, and remained so through the rise of urban living and literacy.
Big polyglot empires needed universal religions, decoupled from particular tribes or places. Monotheism served the purpose best, and the genius of the Jews in establishing the first literate monotheism, around the middle of the first millennium B.C., was a key event. Judaism was tribal, not universal; but when supercharged with the modifications introduced by — mostly, probably, says Wade — Saint Paul, it was universal enough to vanquish the rather tacky Roman pantheon, and to be the foundation for medieval European civilization.
The evolution of religion was very uneven, though, with many vestigial features refusing to fall away entirely. Judaism has retained its tribal flavor; and the major feasts of modern religions are still pegged to the agricultural calendar — Passover, for example, according to Wade, once heralded the beginning of the barley festival. The priest-king principle of the earliest urban societies persists in the British monarch’s claim to be Defender of the Faith. The ecstatic dancing of hunter-gatherer observances was disapproved of by urban priesthoods of the agricultural age, but survives none the less in the Whirling Dervishes of Sufism, and in the rhythmic swaying of African choirs. (See also 2 Samuel, 2.xiv, where King David “danced before the Lord with all his might.”) Religion is very conservative, as one would expect of a belief system laying claim to eternal truth.