Fingerprints of God_ The Search for the Science of Spirituality - Barbara Bradley Hagerty [46]
That is precisely what they found (although, remember, this is a single study). People with a particular variation of the DRD4 gene scored higher on the self-transcendence scale. To a layperson, that particular gene might seem only modestly important: 3.9 percent of the difference in the men’s spirituality scores could be traced back to that particular receptor.12 However, Comings noted that it is rare for a single gene to account for more than 1.5 percent of variance of any behavioral trait.13 He also noted that the dopamine receptor is present in high concentrations in the frontal lobes of the brain, which is the site of many higher human brain functions.
“One could argue,” he and his colleagues wrote, “that spirituality is the quintessence of higher human brain functions.”14 While the scientists cautioned that this particular gene “is not ‘the gene for spirituality, ’ ” it does seem to contribute to a “significant portion” of the variance, or reason, some people are spiritual and others are not.
There is another frequently mentioned suspect in the God-gene lineup: the serotonin system. The serotonin system has intrigued scientists for years because it dramatically alters moods. For example, the drug Ecstasy creates a high by releasing a wave of serotonin. Prozac, Paxil, and Zoloft work more slowly in the system, evening out moods by doing the same thing. And hallucinatory drugs can create a mystical experience worthy of Saint Teresa of Ávila.
In 2003, a group of Swedish scientists led by Jacqueline Borg at the Karolinska Institute in Stockholm tried another approach to determine what role, if any, serotonin plays in spiritual experiences. They used brain scanners. They recruited fifteen healthy Swedish men for a spirituality test. The subjects took Cloninger’s self-transcendence test and then sat for a PET (positron emission topography) scan, which took pictures of their brain activity.15 Researchers cannot measure the amount of serotonin in the brain directly, so they used an indirect method: they measured the activity of the chemical’s docking stations or receptors, and in a particular receptor gene called serotonin 5-HT1A.
To do that, the scientists injected a tracer fluid that acts very much like serotonin into each man’s bloodstream. Then they put the men separately into the brain scanner and watched what the fluid did once it arrived in the brain. They were particularly keen on seeing whether the counterfeit serotonin would bind with serotonin receptors. Their hunch was confirmed: they found a strong relationship between each subject’s serotonin levels and his spirituality score.16 Specifically, this genetic dimmer switch seemed to affect which man believed in God, a unifying force, or phenomena that can’t be explained by “objective demonstration,” and which tended to favor a “reductionist and empirical worldview.”
This suggests, the researchers wrote, that “the serotonin system may serve as a biological basis for spiritual experiences,” and that the variation in this gene “may explain why people vary greatly in spiritual zeal.”17
Researchers in this area remind me of Sherlock Holmes, piecing together scenarios with shards of often conflicting evidence. It is evident that something has happened, but exactly how it happened remains a mystery. So it is with scientists exploring spirituality: they know that millions of people genuinely experience transcendence—but what, exactly, is the mechanics of that feeling? Is it genes, or temporal lobes, or a psychological coping mechanism? Or is