How Religion Evolved And Why It Endures
Robin Dunbar
Pelican, an imprint of Penguin Books, 2023
ISBN 978-0-241-43179-5
Paperback, 230 pages
Reviewed by Joe Szimhart, October 2023
According to the author of How Religion Evolved, the evolution of religion is social or communal evolution with biological underpinnings. Secular approaches to communal living without transcendent beliefs survive one seventh as long as religious communes with transcendent beliefs. Secular communes do not have a policeman in the sky. The transcendent connection to high gods through rituals and doctrine form a strong bond that works better to create cohesion than authoritarian force alone, although both might be present in large movements. The optimal size for a local church or for a congregation is 150 people. The brain of Homo sapiens can retain meaningful memories of friendships of up to 150 people. In mega-churches with thousands of subscribers, the maximum number of meaningful friendships within that larger group remains around 150. Roman military contingents numbered on average around 150. The actual optimal group number is 148, but it is easier to remember rounded up. Science theory likes neat numbers or “elegance,” as my analytical geometry professor told us when I was in college. The number 150, coined as Dunbar’s Number around 1993, is attributed to British evolutionary anthropologist Robin Dunbar who writes in this book:
“The optimal size seems to be quite finely specified at 150 members, and even a modest overshoot in the size of a congregation inexorably results in a loss of coherence. Above about 300 members, a phase shift in the organizational structure is necessary if its size is to be maintained or increased, but at the unavoidable cost of a gradually eroding of the sense of belonging.” (264)
Not everyone agrees with Dunbar’s assertions or his science: For that see footnote 3 below for two salient critiques. Dunbar’s number has become a mini paradigm to the extent that for decades some companies and organizations have organized their employee populations around that number.[1] The verity of Dunbar’s science is not my concern here, though I think it would be a mistake if overvaluing his ideas created a cult around the number 150. Dunbar’s remarks on religion and cults are what interests me here.
Due to what Dunbar calls the social brain with its cognitive capacity fixed by evolution for 200,000 years in Homo sapiens, we function best as group members when our familiar circle of friends reaches between one hundred to two hundred people. In other words, the biological brain has not evolved for cognitive capability (no genetic change) in that time, but the social capacity for adaptation has and has allowed for the success of larger communal groups.[2] But 150 remains as the optimal number of personal friendships in a group due to the sizes of the brain and parts of the brain.
Cultic or religious behavior shifted around 8,000 years ago when doctrinal religion emerged to help manage groups larger than the typical hunter-gatherer groups of 100 to 200 people. The latter might function ritualistically through shamans or seers, but they had no fixed doctrine and no established language sophisticated enough to spread a doctrine. Dunbar states, “While we can have language without religion, we cannot have religion without language” (164). “The issue is language that is sufficiently sophisticated to express symbolic concepts and, perhaps more importantly, the capacity to refer to past and future, since this is something that no animal is able to do” (165).
Hunter-gatherers without transcendent beliefs worldwide would split off into smaller sub-clans when their number went beyond 150. During the Axial Age around 2000 to 2500 years ago, our major world religions emerged, adding another stage of social evolution to influence much larger populations. Despite the modern drivers toward a secular society since the Enlightenment era, the social brain that emerged around 200,000 years ago continues to drive us toward religious behavior if we intend to sustain large groups of 150 or more. We find examples of this during the last century in ultra-nationalist politics most recently evidenced by the cult of Eurasianism informing Russian policies. Dunbar concludes his book with this:
“In short, it is difficult to see any convincing evidence for anything that will replace religion in human affairs. Religion is a human trait. The content of religion will surely change over the longer term, but, for better or for worse, it is likely to remain with us.” (268)
In my self-published memoir of how I got into cult intervention, I stated in the prologue that cultic behavior drove human social evolution.[3] After reading this book by Dunbar, I better understand why I said that. How Religion Evolved condenses decades of research from anthropology, neuroscience, history, and language development into a readable reference book for the non-specialist in those fields. Beyond the facts I mentioned above as a teaser for what you will find in this book, my intent in this review is to concentrate on what this book reveals about the formation of cults and sects.
Chapter 9, “Cult, Sects and Charismatics,” appears after chapter eight established that “A Moralizing High God, of the kind found in many of the world religions, seems to represent a final stage of development that appears only when the civic units are very large” (212). If we follow the long-established pattern of limits to harmonious human group cohesion at 150, the pattern Home sapiens established as hunter- gatherers for 95% of our existence, we can grasp why breakaway sects and cults continue to emerge from and outside of large, established religions. The familial harmony tends to break down in larger groups, whether or not we agree with Dunbar. We note this especially when a rebel charismatic leader presents a new version of transcendent connections to the gods, the universe, or God. Dunbar gives many examples of this throughout history, diminishing the popular bias in my generation that cults suddenly appeared as a major problem after World War 2 with the emergence of anti-cult groups and deprogrammers. We have always had this problem of emerging new religious groups. How we deal with the problem legally, socially, and scientifically is what continues to change.
Chapter 9 begins with, “All religions begin as cults, built around a charismatic leader.” Dunbar goes on to unpack this claim while defining religion in the broad sense of communal cohesion with belief in a transcendent god or force. Transcendent experience tends to be shared by the cult founder who may act as the cult leader—not all cult founders are the leaders. For example, I recall exit counseling members from a cult called Miracle of Love that was based on the charismatic experience and teaching of a former member of the Hare Krishna movement, but his partner, who called herself Kalindi, was the acting leader and manager of the group. The founder, in my view, was mentally ill and could not function as a leader. His attendants helped feed, clothe, and bathe him.
Dunbar uses a little-known, early 20th Century cult called The Panacea Society founded and led by Mabel Barltrop as a case study. He chose the group because, despite its eccentricities, it was never viewed as dangerous or more than an idiosyncrasy by the local Church of England. At the time of her husband’s death in 1909, Mabel Barltrop was in treatment at the local asylum for extreme depression. She later became inspired by the teachings of 18th Century prophetess, Johanna Southcott. Barltrop’s movement grew to around seventy committed (mostly older female) members by 1930 with as many as 1,300 ‘sealed’ members. As the movement grew, Barltrop was obliged to establish formal rules. The Panacea Society fell apart soon after the founder died in 1934. “The last surviving member died in 2012” (219). Dunbar uses this example as a typical start-up cult that fades away after the charismatic leader dies. Most new religious movements lack the capacity for the viable governance and doctrinal formation required to enter a much larger phase of group size. Dunbar also examines, in brief, The Ant Hill Kids, the Branch Davidians, Rajneeshpuram, The People’s Temple, Tenrikyo, the Cathars, and several others.
Evidence presented in this book shows that psychoactive substances and natural endorphin (endogenous morphine) stimulation through chanting, dance and other rituals enhanced early human religious development in the social brain and they still do. Any number of new cults arise around someone who experiences trance and transcendental awareness during or after a severe illness, an existential crisis, a neurological breakdown with schizophrenic symptoms, a psychoactive drug effect, extreme fasting, or days or weeks of sitting still and other over-the-top physical exertions. Out of body or near-death experiences account for many stories about transcendental journeys to a heaven, hell, or other planets—not to mention meetings with angelic beings, gods, and ancestors. Transcendent experience, whatever the stimulation, helped to form the social brains of modern humans.
“A synthesis of the clinical and neurobiological evidence concluded that the same brain centers are overactive in schizophrenia, the manic phase of bipolar disorder, and hyper religious behavior” (228). Also, schizotypal personality traits like all personality traits “are simply one extreme of the normal distribution range into which we all fall…” (229). It is worth reading the science behind this assertion that Dunbar provides in detail. I can only agree from experience after working in the crisis and intake department of a psych hospital for twenty-five years. Religious preoccupation appeared in my mental status evaluations of well over half the patients I processed with the diagnoses mentioned above. Grandiose claims by unmedicated patients to be God or the voice for God were so common as to be expected.
Though it is rare in my experience that someone diagnosed with schizophrenia after hospitalizations can ever function well enough to manage a cult following and likely will not want to once properly medicated, charismatic leaders with strong schizotypal personality traits can manage a cult following. Schizotypal traits can make a leader far more interesting to true believers who see evidence of transcendence in the traits wherein non-believers see annoying, manipulative, and deceptive behavior.
Dunbar presents the science supporting the “orders of intentionality” for the evolution of mentalizing abilities in primates in chapters five and seven. A monkey at the first order of cranial volume that supports a simple level of intentionality can believe that it is raining. Monkeys have no religious capacity. An ape at second order can believe that you think that it is raining but cannot translate this into religion. At the third order, Homo erectus could likely believe that you think that God exists as a religious fact but that will not create religion. Neanderthal and Homo heidelberg at the fourth order could believe that God exists and intends to punish us as a personal religion. Only at the fifth order in anatomically modern human adults can we believe that you think that we both know that God exists and intends to punish us, and that leads to communal religion (119; 168). Orders of intentionality have to do with the complexity and sophistication of language that in some modern humans can reach a sixth order. The orders of intentionality parallel language development in stages of human brain growth. For example, a teenager might be capable of third or fourth order intentionality but not fifth. Thus, communal religion requires a minimum of fifth order cranial volume that supports advanced language development as evidenced in anatomically modern human adults.
There is so much more I could say about this book by Dunbar, but for this review I hope to whet the appetite of anyone who is interested in the science behind what we can know and want to know about religious behavior. Of course, since this is science, as I mentioned above, there are approaches to evolution and brain function that would dispute Dunbar’s number and his assessment of orders of intentionality related to cranial volume. For criticism, you can go to the note below.[4]
[1] “The Rule of 150 – Dunbar’s Number and business growth” by Rob, Cultivated Management, 12/11/2017.
https://cultivatedmanagement.com/the-rule-of-150/
[2] For example, we can take a healthy infant from an existing hunter-gatherer tribe and raise that human to be a modern plumber, an engineer, or a philosopher. The cranial volumes of ancient hunter-gatherers are the same as modern humans, although the shapes of brains may vary.
[3] Szimhart, Joseph (2020) Santa Fe, Bill Tate, and me: How an artist became a cult interventionist, page 1
[4] “’Dunbar’s Number’ Deconstructed” by Patrik Lindenfors, Andreas Wartel, and John Lind, The Biology Letters of The Royal Society, 05 May 2022: https://doi.org/10.1098/rsbl.2021.0158
“Dunbar’s Number: Group Size and Brain Physiology in Humans Reexamined” by Jan de Ruiter, Gavin Weston, and Stephen Lyon, American Anthropologist, 25 November 2011: https://anthrosource.onlinelibrary.wiley.com/doi/abs/10.1111/j.1548-1433.2011.01369.x