The human insula (narrative below)
Many psychologists1 and biologists2 have speculated on the biological origins of spirituality over the past 100 years or more . We are beginning to make progress in this regard, though a definitive conclusion seems quite far away.
Comparing religion to language is helpful, as Nicholas Wade points out in his book, The Faith Instinct3:
"Like language, religion is a complex cultural behavior built on top of a genetically shaped learning machinery. People are born with innate instincts for learning the language and the religion of their community. But in both cases culture supplies the content of what is learned. That is why languages and religions differ so widely from one society to the next, while remaining so similar in their basic form."
Language is a uniquely human capacity and its acquisition by babies is a fascinating field of study. Babies have an innate drive to speak. This drive to speak is so powerful that congenitally deaf babies start babbling without ever having experienced human voice, or indeed, any sound.
A genetic program seems to be unfolding which may get molded based on each baby's linguistic environment4. Almost every baby learns to talk in their mother tongue/s without any formal training. Contrast this to reading or writing which need to be formally and laboriously taught over a long period of time.
Is the spiritual instinct closer to language or to reading / writing? We cannot really be sure at this point.
Attempts to examine the genetics underlying the religious instinct using approaches similar to those used to study the genetics of language acquisition have been made. They have not yielded any positive correlations so far between religious attitudes and genetics5, though this may change given genomic technology has advanced considerably in the last few years.
Deficits in language acquisition are relatively easy to measure and obvious. If we accept the notion of a biological spiritual instinct, how does one measure it in a universal way across our entire species?
A complimentary approach is to identify the 'learning machinery' underpinning the spiritual instinct. What brain structures or circuits might underlie spiritual / religious / mystical experiences?
Epilepsy, surprisingly, may have some clues.
A strong note of caution before we proceed:
The evidence is anecdotal at this point and has been hard to verify across multiple centers around the world, except for sporadic reports. Given that the original observations were made centuries ago, the lack of wide-spread, corroborating observations suggests many null or contradictory findings have not been emphasized in the literature.
Furthermore, there are no mechanistic explanations, experimental manipulations or a comprehensive theory framing these observations, though there are a few initial attempts at all of these. Hence, the issue is far from resolved and there is no scientific consensus. Rather, these observations may be regarded as controversial. With that said, let us take a skeptical look.
The WHO estimates more than 50 million people around the world live with epilepsy. Furthermore, up to 10% of the general population experiences a brain seizure during their lifetime (epilepsy is defined as two spontaneous seizures at least 24 hours apart). That is, a large subset of the world population has at least second hand experience with this disease.
A seizure begins with runaway electrical activity in brain cells which can lead to many different symptoms based on the location and extent of the electrical 'storm'.
Seizures can cause a variety of symptoms commonly beginning with visceral symptoms called auras (feelings of internal warmth / cold / energy traveling within the body) which can progress all the way to dramatic whole body convulsions, depending on the extent and duration of the seizure.
Epilepsy has forever been linked to to supernatural forces over the centuries, with written records dating back 3000 years at least. Even today, it is widely feared and misunderstood. Epileptics are frequently stigmatized socially due to widespread beliefs of demons or spirits possessing them during their fits.
Temporal lobe epilepsy (TLE) is a type of focal epilepsy and has been associated with symptoms like 'deja vu' and 'memory reminiscences'. It can very rarely -total of 50 cases documented worldwide so far- begin with an 'ecstatic aura' with no other recognizable external symptoms.
These patients describes their auras in vivid terms using phrases like:
"feeling of complete serenity, total peace, no worries", "...I do not fear death anymore...", "...well-being inside...sheltered from anything negative...", "...inner body rises from an unalterable bliss", "feeling of pleasure. I felt intensely well...", "... as if I rose a little into the air...", "well-being of almost spiritual consonance.", "immense joy...total presence..., unbelievable harmony of my whole body and myself with life, with the world, with 'All'".6
Such experiences have convinced many people across the planet and through the centuries, of the existence of something supernatural, something normally invisible to humans that can only be perceived in such states. Of course these are all anecdotes and unverifiable subjective experiences but, that is no argument for someone who experiences it first hand.
Several researchers have diligently pursued the biological origin of these ecstatic seizures within the brain. Work by a research group, lead by Dr Fabienne Picard at the University Hospital of Geneva, stands out particularly in the current literature.
Her groups research has homed in on a small region of the brain known as the anterior insula (see figure at beginning) as a likely origin of these ecstatic auras. This group of clinical epileptologists has over the years investigated these auras using a combination of imaging and electrical micro-stimulation of the brains of their patients.
Electrical micro-stimulation is done using fine electrodes implanted surgically in the brain. This is part of a procedure to identify the epileptic zone which is then removed surgically, thereby curing the epilepsy. Patients do not experience any pain during micro-stimulation and can remain conscious and able to interact and answer questions normally.
A handful of patients so far, have reported ecstatic auras when their anterior insula was micro-stimulated electrically7. This work is almost impossible to do in other parts of the world and has taken over 20 years of effort!
Keeping in mind the caveats mentioned earlier, this could be a potential entry point to unraveling the brain circuitry underlying the religious instinct, eventually leading to a mechanistic explanation and an overarching theory regarding the role of this instinct in conferring adaptive advantage to individuals possessing it.
Imagine a day in the future when we have unraveled every detail of the brain circuit underlying the mystic experience and are able to induce it in anyone who wishes and has the necessary circuits. What then? That person may experience something unique that very likely depends on their personal history, culture and beliefs and no else will be able to truly ‘see’ what they have seen though we may record detailed images of their brain experiencing that vision. No one else will ‘feel’ what they feel, though the underlying mechanics be perfectly understood and followed electrically.
We will be left with this final analysis by J Wentzel Van Huyssteen8, a theologian who passed away this year. He concluded that human cognition supersedes biology because knowledge and beliefs can promote survival without genetic change:
It is in this sense, when considering the nonadaptive aspects of our cognitive drives, that we can say that in human knowledge, in moral awareness, in aesthetic appreciation, and in religious awareness we transcend our biological origins. This perspective helps us to see human cognition as the mediator between biology and culture, and cultural evolution as requiring explanations beyond the biological theory of evolution (p. 97).9
William James. “Varieties of religious experience” 1902
Edward O. Wilson. “On Human Nature” 1978
Nicholas Wade. “The Faith Instinct: How Religion Evolved and Why It Endures” 2009.
Graham, Sarah A., and Simon E. Fisher. "Understanding language from a genomic perspective." Annu Rev Genet 49.1 (2015): 131-160.
D’Onofrio, Brian M., et al. "Understanding biological and social influences on religious affiliation, attitudes, and behaviors: A behavior genetic perspective." Journal of personality 67.6 (1999): 953-984.
Picard, Fabienne, and A. D. Craig. "Ecstatic epileptic seizures: a potential window on the neural basis for human self-awareness." Epilepsy & Behavior 16.3 (2009): 539-546.
Picard, Fabienne, Peter Bossaerts, and Fabrice Bartolomei. "Epilepsy and Ecstatic Experiences: The Role of the Insula." Brain sciences 11.11 (2021): 1384.
J. Wentzel Van Huyssteen. “Alone in the World?: Human Uniqueness in Science and Theology” 2006.
Coles, Alasdair. “God, theologian and humble neurologist.” Brain (2008),131,1953-1959.