In search of the religious gene

Nicholas Wade in The Faith Instinct: How Religion Evolved and Why it Endures concedes that there is no hard-evidence of the genetic basis for religion, but his inferences are compelling:

“An indirect approach to the genetic basis of religious behavior is through psychological studies of adopted children and of twins. Such studies pick up traits that vary in the population, such as height, and estimate how much of the variation is due to environmental factors and how much to genetics. But the studies cannot pick up the presence of genes that don’t vary; genes for learning language, for example, are apparently so essential that there is almost no variation in the population, since everyone can learn language. If religious behavior is equally necessary for survival, then the genes that underlie it will be the same in everyone, and no variation will be detectable.

“Religious behavior itself is hard to quantify, but studies of religiosity— the intensity with which the capacity for religious behavior is implemented—have shown that it is moderately heritable, meaning that genes contribute somewhat, along with environmental factors, to the extent of the trait’s variation in the population. “Religious attitudes and practices are moderately influenced by genetic factors,” a large recent study concludes. [Kindle locations 745-758]

Wade’s reference “40” is “40 Brian D‘Onofrio et al., “Understanding Biological and Social Influences on Religious Affiliation, Attitudes, and Behaviors: A Behavior Genetic Perspective,” Journal of Personality 67, no. 6 (1999): 953-84.”

“Another survey finds that “the heritability of religiousness increases from adolescence to adulthood,” presumably because the influence of environmental factors decreases in adulthood (when you leave home you go to church if you want to, not because your parents say so). 41. Wade’s reference here is “41 Laura B. Koenig et al., “Genetic and Environmental Influences on Religiousness: Findings for Retrospective and Current Religiousness Ratings,” Journal of Personality 73, no. 4 (2005): 1219-1256.”

Further down Wade writes, “In the absence of direct evidence about the genes underlying religious behavior, its evolutionary basis can be assessed only indirectly. The effect of cultural learning in religion is clear enough, as shown by the rich variety of religions around the world. It’s the strong commonalities beneath the variations that are the fingerprints of an innate learning mechanism. These common features seem very unlikely to have persisted in all societies for the 2,000 generations that have elapsed during the 50,000 years since the ancestral human population dispersed from its African homeland, unless they have a genetic basis. This is particularly true given the complexity of religious behavior, and its rootedness in the emotional levels of the brain.

“To no less an observer than Darwin himself it seemed that religion was like an instinctive behavior, one that the mind is genetically primed to learn as indelibly as the fear of heights or the horror of incest. His two great books on evolution, Origin of Species and Descent of Man, have nothing directly to say about religion but in his autobiography, written in his old age, he was more explicit about this controversial topic. He wrote, “Nor must we overlook the probability of the constant inculcation in a belief in God on the minds of children producing so strong and perhaps an inherited effect on their brains not yet fully developed, that it would be as difficult for them to throw off their belief in God, as for a monkey to throw off its instinctive fear and hatred of a snake.” [Charles Darwin, Autobiography (New York: Norton, 1969), 93.] [Kindle locations for the above two paragraphs are 764-775]

Comment: I hope I’ve left Wade’s argument as far as he’s developed it intact, but I was especially interested in the statement “studies of religiosity— the intensity with which the capacity for religious behavior is implemented—have shown that it is moderately heritable,” and ““the heritability of religiousness increases from adolescence to adulthood.” I have run across similar references in regard to other “somewhat” or “moderately” heritable phenomena. In those other references the term “trigger” was used, if I remember correctly. In other words we, or perhaps just certain people, have genetic material within us that is quiescent until something “triggers” it. Then the genetic material becomes active. I am tempted to urge, “abandon all Darwinian syllogisms, ye who would enter here” except Wade is clearly a Darwinian and fits all his inferences (thus far) back into the Darwinian schema, and he seems to have especially succeeded in this case. He quotes Darwin as writing, “Nor must we overlook the probability of the constant inculcation in a belief in God on the minds of children producing so strong and perhaps an inherited effect on their brains not yet fully developed, that it would be as difficult for them to throw off their belief in God.” “Perhaps an inherited effect”? How very unDarwin of you.