A God Gene?

Let’s continue talking about God and evolution, a combination that generates more than its share of high-energy radiation, most of it in the infra-red rather than the visible spectrum. But instead of looking into the alleged cohabitation or, alternatively, the conflict between the two, let’s look at religion as an evolutionary mystery: Nearly all human societies have some sort of God concept, and most people (excepting in some modern northern European societies) believe in some sort of God. Which leads one to ask, Why? In later posts, I’ll explore some possible explanations, hypotheses as to the “adaptive significance” of religious belief. For starters, let’s look into what may seem to be the simplest, most direct explanation: that belief in God is widespread because of a “God gene.”

Right off, we should note that even if there were such a gene, this would actually explain very little, since the question would remain: Why is there such a gene (or such a God-seeking brain region, or God-seeking hormone, etc.)? An evolutionary mystery isn’t solved by pointing to a particular gene, brain region or hormone, just as a murder mystery isn’t solved by pointing to a particular weapon, even if it turns out to be the “correct” one. The detective wants to know who wielded it, and why. So even if there were a “God gene,” we’d still have work to do. But first, let’s take a look at this God gene notion.

The claim was made explicitly by Dean Hamer, a geneticist who should have known better, but I suppose he simply wanted to sell books. Thus, in The God Gene: how worship is hard-wired into our genes, Hamer hyperventilated over a particular genetic variant, known as VMAT2, which—along with many others—helps code for the production of proteins that do much of the work in our brains: so-called neurotransmitters and neuromodulators. Different versions of VMAT2 exist in different people (the technical term is that it is “polymorphic”). And this, in turn, could contribute to why different people respond differently to different stimuli and situations.

More specifically, Hamer found a weak but seemingly genuine correlation between the presence of the VMAT2 gene and a tendency to feel connected to the world and a willingness to accept things that cannot be objectively demonstrated. In a review of The God Gene in Scientific American, Carl Zimmer wrote that a more accurate title would have been “A Gene That Accounts for Less Than One Percent of the Variance Found in Scores on Psychological Questionnaires Designed to Measure a Factor Called Self-Transcendence, Which Can Signify Everything from Belonging to the Green Party to Believing in ESP, According to One Unpublished, Unreplicated Study.” On another occasion, incidentally, Dr. Hamer also reported discovering a “gay gene,” a finding that now appears equally questionable even as the evidence is now irresistible that there nonetheless is a complex pattern of DNA underlying gay-vs-straight sexual orientation. (Perhaps there is also a gene for finding or at least reporting the existence of genes that may or may not really exist ...)

Interestingly, there is some evidence pointing to a general genetic underpinning when it comes to religion. A study characterized the religious inclinations of 31 pairs of fraternal twins who had been reared apart, comparing their pattern of similarity and difference with that found among 53 pairs of identical twins also reared apart. Fraternal twins share, on average, 50% of their genome whereas identical twins are genetically identical, sharing 100% of their genes. Interestingly, when it came to religious tendencies, the correlation between the identical twins was roughly double that of the fraternals. A similar result was found in an Australian study involving more than 4,000 twin pairs from Australia and England. In a sense, therefore, we appear to be genetically hard-wired for religion. But what does this mean? Clearly, it isn’t for a particular religion; there are more than 7,000 identified varieties.

Consider this: It has been well demonstrated that a particular human genetic variant, by modifying the way its carriers metabolize the neurochemicals dopamine and serotonin, generate a predisposition toward risk-taking. This general inclination manifests itself in specific behaviors, such as a fondness for roller-coasters, or for fast sports cars. This does not mean that there is a gene “for” roller coasters, or “against” sedate Volvo sedans. Rather, our genetic make-up often predisposes us in one direction or another, with the specifics determined by what’s on offer. Not only are there no genes for Buddhism as opposed to Hinduism, or for Jewishness as opposed to Christianity, there are no genes for religion as opposed to atheism.

But there can certainly be genes that make people more or less likely to believe things without empirical evidence, more or less likely to accept the authority of others, more or less likely to enjoy ritualized behaviors such as singing in a chorus, and so forth. Instead of thinking about genes “for” religion, it is more useful to consider genes that result in an openness or susceptibility or inclination for certain kinds of experiences that manifest themselves via religion. (Incidentally, this is very much what evolutionary biologists have in mind when we discuss the biological underpinnings for other behavioral traits, such as altruism, aggressiveness, parental love, honesty or dishonesty in communication, and so forth.)

For example, even if, as seems almost certain, there are no genes for counting or doing arithmetic, it is equally certain that there are genes whose effects include having the ability to do arithmetic (as well as the ability to think straight, understand basic logic, etc.). And there is no particular mystery why such a capacity hasn’t been selected against: It can be very useful to keep track of the numbers of things. And very little liability. But what of religion?

In subsequent posts, I’ll review some of the major hypotheses for why religion is so widespread in Homo sapiens. (And for the umpteenth time, let me emphasize that these hypotheses have nothing whatever to do with the question of whether religion is “true” or “false.”)