Since the 19th century, thinkers like Ludwig Feuerbach, Friedrich Nietzsche, and Sigmund Freud have theorized religion as a strictly psychological and anthropological phenomenon born of the tendency of the human mind to project its contents out into the heavens. The Darwinian revolution provided another framework—one grounded in experimental science—to explain religion. Social scientists like Pascal Boyer have integrated these paradigms in comprehensive accounts of the origins of religious belief, and in theories like E.O. Wilson’s Sociobiology, evolutionary biology provides an explanation for all social phenomena, of which religion is but one among many human adaptations. Advances in neurobiology have furthered scientists’ understanding of religion as a product not only of human consciousness, but also of the physical structure of the brain. In experiments like the “God helmet,” for example, scientists can induce religious experiences by prodding certain areas of subjects’ brains.
It is in this context of psychology, anthropology, and evolutionary and neurobiology that we need to situate the lecture above from Stanford professor Robert Sapolsky. Where many critics of religion explicitly reject religious authority and belief, Sapolsky, though himself “stridently atheistic,” has no such agenda. As an article in the Colorado Springs Independent puts it, “he’s no Christopher Hitchens.” Sapolsky freely admits, as do many scientists---religious and non---that religion has many benefits: “It makes you feel better. It tends to decrease anxiety, and it gets you a community.” However, he claims, these positives are the result of evolutionary adaptations, not proofs of any supernatural realm. In fact, religiosity, Professor Sapolsky argues above, is biologically based and related to seemingly much less adaptive traits like obsessive compulsive disorder, schizophrenia, and epilepsy.
Part of a lecture course on “Human Behavioral Biology” at Stanford, the religion lecture is one Sapolsky admits he is “most nervous for, simply because this one people wind up having strong opinions about.” As he moves ahead, he presents his case (with occasional interruptions from his students) for religiosity as a result of natural selection, connecting belief to the selection of genes for diseases like Tay-Sachs, the existence of which can help to explain dispiriting historical cases like the European Pogroms against the Jews in the Middle Ages. Throughout his lecture, Sapolsky makes connections between religiosity and biology, theorizing, for example, that St. Paul had temporal-lobe epilepsy.
At the end of his lecture, around the 1:19:30 mark, Sapolsky issues a disclaimer about what he’s “not saying”: “I’m not saying ‘you gotta be crazy to be religious.' That would be nonsense. Nor am I saying, even, that most people who are, are psychiatrically suspect.” What he is saying, he continues, is that “the same exact traits which in a secular context are life-destroying” and “separate you from the community” are, “at the core of what is protected, what is sanctioned, what is rewarded, what is valued in religious settings.” What fascinates Sapolsky is the “underlying biology” of these traits. Sapolsky even confesses that he "most regrets" his own break with the Orthodox religion of his upbringing, but that his atheism is something he “appears to be unable to change.” The questions Sapolsky asks broadly cover the physical determinism of gaining faith, and of losing it, which he says, is “just as biological.” What we are to make of all this is a question he leaves open.
You can watch Sapolsky’s full series of lectures on Behavioral Biology here, and for a fully annotated summary of his religiosity lecture above, see this site.