Eighteen thousand. This is the rough estimate, made by various anthropologists, of deities that human religions have worshipped and then forgotten throughout their history. Fascinating, isn't it? Homo sapiens seems to possess a sort of evolutionary compulsion to create superior entities, to project beings with supernatural powers into the sky.
And this is not a marginal phenomenon: 80% of the world's population (I am no exception) today considers themselves in some way religious or spiritual. But why? What drives our brains to build cathedrals, to kneel in prayer, to seek transcendent meaning? A neuroscience study may have identified the brain area responsible for this peculiar human trait, and surprisingly, it is not where you would expect.
An ancient structure for millennial religions
Neuroscientists They've finally mapped the brain circuitry of spirituality, and the surprise is great: it is not an evolutionarily recent area in the cortex, as many would have bet, but a primitive structure in the brainstem called periaqueductal gray matterYes, sir: our sophisticated spirituality, with its elaborate religions, theologies and complex rituals, may have its origins in one of the oldest and most primitive parts of our brain.
This neural circuit, according to the study published in Biological Psychiatry (I link it here) plays a key role in our responses to fear, pain, and altruistic behavior. It is no coincidence that people with damage to this area often develop delusions, almost as if their “spiritual thermostat” had been tampered with.
Evolution, that great engineer, seems to have selected a brain that readily accepts a world of supernatural causes and beings, however logically absurd it may seem. But why? The answer is pragmatic: spirituality offers tangible benefits for survival and reproduction. It reduces our fear of living in an unpredictable world and promotes altruistic behaviors that strengthen social cohesion. Spirituality, friends, is a superpower.
Modern Technologies for Ancient Mysteries
Scientists didn't limit themselves to theory, however. They used an arsenal of non-invasive tools (from electroencephalography to the structural and functional magnetic resonance imaging, up to positron emission tomography) to study the brains of people practicing different religions while in a state of prayer or meditation.
They observed unique activity in different brain regions, including areas of the frontal cortex. But the real star of the show turned out to be that little structure in the brainstem, the periaqueductal gray I was telling you about, which seems to be the conductor of our spiritual experience.
One god sets, another rises
Let's think about Ra, the powerful Sun god worshiped by many cultures for millennia, now almost completely disappeared from collective memory. If history is any guide, many of the deities currently worshiped will suffer the same fate, replaced by new divine entities that will better respond to the cultural and emotional needs of future generations.
Will we continue to worship new gods in the future? This question fascinates me. With our brains wired for spirituality, it’s hard to imagine a future completely devoid of transcendent beliefs. They may not worship Zeus or Yahweh, but I bet our descendants will still find something “bigger” to worship. I hope not AI. Perhaps a personified ecological system, like Eywa from Avatar? Or a cosmic entity yet to be conceived?
Spirituality must offer something tangible that enhances procreation and survival. Otherwise, evolution would have selected brains and organisms averse to such costly behaviors as building giant pyramids to house the dead, blowing oneself up for the pleasures of heaven, or sacrificing one's children as a measure of devotion to one's deity.
Religions, the neural heritage
What makes this finding particularly fascinating is that the tendency to rely on religions, like the brain wiring patterns that underlie specific personality traits, is thought to be heritable. We are literally born with a predisposition to believe.
Skeptics might argue that reducing spirituality to neural circuits is reductive. And perhaps they are right. But then again, if you think about it, there is something poetic in the idea that our ability to imagine the divine, to create elaborate systems of meaning, to build majestic cathedrals and compose celestial music can emerge from a small group of cells in our brain stem.
In the end, perhaps the greatest wonder is not the gods we created, but the brain that imagined them. That too is a mystery, a miracle of sorts. No?
Others references:
Rim J et al (2019) Current Understanding of Religion, Spirituality, and Their Neurobiological Correlates
HARVARD REVIEW OF PSYCHIATRY, Vol 27, P 303-316
Mehta SK et al (2019) Can Religiosity Be Explained by 'Brain Wiring'? An Analysis of US Adults' Opinions
