ABOVE: Prometheus, October 15, 2022

Since the advent of functional neuroimaging in the early 1990s, the temptation to peek into the brains of people praying, meditating, or speaking in tongues has been irresistible. As is often the case when new territory is explored, these studies have emphasized descriptions of the landscape more than the testing of hypotheses. The neuroscience of religious experience has come a long way since those early years, but it still needs specific and testable hypotheses that lead to good experimental questions if it is to thrive.

In my new book, The Phantom God: What Neuroscience Reveals about the Compulsion to Believe, I argue that neuroethology offers a promising approach. This branch of neuroscience explores how the brains of highly specialized animals generate behaviors that serve well-understood roles in their reproductive success. A thorough understanding of those behaviors is the key to specific and testable hypotheses at the level of neural circuitry. Prominent advances in neuroethology have elucidated the development of song in young songbirds, communication and navigation using electric fields in weakly electric fish, and the formation of sexual pair bonds in monogamous prairie voles. Do we understand human religiousness well enough, in terms of the underlying selective pressures, to make specific hypotheses about its implementation in the brain? I think we do.

Why do believers tell you their God will damn you to hell, yet in the same breath insist that He loves you unconditionally? That they don’t notice this contradiction strongly suggests that the dichotomy arises from distinct and powerful intuitions, not careful reasoning. That the intuitions are ubiquitous across human cultures suggests they are innate—as do twin studies, which show that religiousness is significantly heritable. And if our tendency to believe in two-faced gods is a product of evolution, then those faces likely correspond to two distinct selective pressures. More than a century of research in anthropology, psychology, and sociobiology explains the belief in cruel and judgmental gods as an adjunct to human social cooperation. Fealty to the gods is a reliable demonstration of tribal loyalty, provided the religion demands costly, hard-to-fake sacrifices as proof of devotion. By contrast, the unconditionally loving side of God did not come under rigorous empirical scrutiny until the 1990s, with the pioneering work of psychologist Lee Kirkpatrick at the College of William and Mary. His attachment theory of religion posits that, for many believers, God is an attachment figure in the same way parents are to small children, and there is now extensive evidence supporting this idea.

          Book cover of The Phantom God by John C. Wathey
Prometheus, October 15, 2022

Yet puzzles remain. Attachment security interacts with the effects of parental religiousness in complex ways. For example, adults who had insecure attachment to nonreligious parents tend to become religious as adults, typically through sudden religious conversion in a time of crisis. But these insecurely attached people see themselves as unlovable and others as untrustworthy. Why would they suddenly trust in God and seek divine love? There must be something else going on, something not accounted for in attachment theory. In wrestling with this question in his 2004 book, Attachment, Evolution, and the Psychology of Religion, Kirkpatrick suggested that “something happens to a sizable minority of these individuals later in life that in effect activates an otherwise dormant love mechanism,” though he did not know what that mechanism might be. Here, the perspective of neuroethology can help.

Just as newborn infants have a language-expectant and a face-expectant cortex in separate parts of the temporal lobe, I suggest they have mother-expectant circuitry in those brain regions that will ultimately support social behavior in adulthood. This innate neural model of a mother gives the neonate an expectation of a primordial savior—a being who knows the infant’s needs, is able to help, wants to help, and will help when she hears crying—priming the infant for attachment and serving as a foundation for adult social behavior. I also suggest that this innate model persists into adulthood and normally lies dormant, much as some innate behaviors of newly hatched birds and sea turtles do. In times of desperation, however, the innate model can be activated in an adult, spawning the illusion of the presence of an unconditionally loving savior.

Why do believers tell you their God will damn you to hell, yet in the same breath insist that He loves you unconditionally?

When seen in this light, the feeling of God’s presence resembles an equally compelling illusion long familiar to neurologists: the phantom limb of the amputee. Both are illusions of embodiment. Just as a phantom limb is conjured by the brain’s expectation that the limb exists, so is a mystical presence by the brain’s expectation of a primordial savior. Neurologist MacDonald Critchley noted that related phenomena—the illusion that another person is nearby and the strange feeling that part of your body does not belong to you—share a common neural substrate, with both symptoms sometimes occurring in the same patient.

My hypothesis does not explain everything about religion, but it offers a plausible candidate for the dormant love mechanism imagined by Kirkpatrick, and it suggests a new strategy for exploring the neural basis of religiousness: follow the neural pathways of early infancy. It draws connections to research previously considered unrelated to religiousness, such as the cognitive and perceptual capacities of human neonates and mother-infant bonding in nonhuman mammals. It also suggests answers to longstanding puzzles, including the tenacity of faith, the greater religiousness of women relative to men, the religious obsession with sex, and “the mystery of elite religious scientists.” Best of all, it makes testable predictions.

Although early attempts at exploring the neuroscience of religiousness met with some derision, recent landmark studies from the labs of Uffe Schjødt of the Aarhus University in Denmark, Harvard’s Michael Ferguson, and others demonstrate the efficacy of studying religious experiences of deep personal relevance to the subjects. By itself, neuroscience may not be able to demystify such experiences, but in conjunction with rigorous testing of hypotheses grounded in ethology, it can. In this light, we may come to see religion as a completely natural phenomenon with deep biological roots.

See “Religion on the Brain

John C. Wathey is a retired neuroscientist and computational biologist who now indulges a lifelong fascination with the biological roots of religious emotions and intuitions. Read an excerpt of The Phantom God: What Neuroscience Reveals about the Compulsion to Believe.