Sunday, February 23, 2014

The God gene ten years later

It has been almost two years since the “God particle” was found and almost ten years since the “God gene” was allegedly found. Further research into the Higgs Boson seems to confirm the original reports from 2012. However, the God gene hypothesis has not fared so well. In nearly ten years, no studies have confirmed the existence of a genetic basis in humans for belief in the supernatural.

The so-called God gene discovery began in 1998, when Dean Hamer, geneticist at the National Cancer Institute, was conducting a study of cigarette smoking and cancer. As part of the study, a standardized 240-question personality test was given to 1,000 subjects entitled the Temperament and Character Inventory (TCI). Among others, one of the traits measured was self-transcendence, or the ability to lose oneself in an experience. (Why this was included in a study of cigarettes and cancer is not clear.) Hamer then branched off this study to spirituality and began to examine particular segments of the human genome. He narrowed the field to specific genes that play a role in the production of monoamines, such as serotonin, and norepinephrine and dopamine. These regulate functions such as mood and can be manipulated by antidepressant psychotropic medication.

Hamer noticed that volunteers who scored high on the self-transcendence test had a variation in a gene known as vmat2 – vesicular monoamine transporter. Those with the nucleic acid cytosine in a particular location on the gene ranked high on the personality test and those with adenine in this location ranked low. [1] Even Hamer pointed out that the human genome and personality are complex and a single change in one position of a gene would not likely be the sole determining factor, stating “"The specific gene I have identified is by no means the entire story behind spirituality”. Nonetheless, in 2004, Hamer published a book titled The God Gene: How Faith is Hardwired into Our Genes.

Scientific American writer Carl Zimmer noted that Hamer’s 2004 book was premature since the genetic link between VMAT2 and self-transcendence had not been replicated by other studies and the relevance to humans had not been demonstrated. Rather than “The God Gene”, Zimmer proposed a more appropriate title for the book: “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.” [3]

It should be noted this is not the first time Dean Hamer has made the news. In 1993, he created a media splash when it was reported that he found a genetic basis for male homosexuality. He found a marker in the Xq28 region of the X chromosome on an allegedly statistically significant percentage of those subjects tested. [2] However, in more than 20 years, no other researchers have been able to replicate the study.

Those who are genetically predisposed – or as Lady Gaga would sing “born this way” – will tend to believe in some higher power or spirit world and those who lack the genetic marker will probably not believe. So, what would be the logical conclusion of this line of reason? First, this means a real god is less likely since belief is simply a genetic tendency, probably left over from our evolutionary survivalist past. Second, non-spiritual persons are less likely to be culpable for any moral failures since they are simply acting as their godless conscience leads. If a marker could be found for belief in God, would that be a form of genetic hyper-Calvinism, in which some people are predetermined to believe and others to not believe?

Are some people more predisposed toward some type of spirituality due to genetics, environment, or both? Probably to some degree. In the same manner, some people may be more prone to alcoholism, altruism, or violence. A predisposition has no bearing on truth or morality. Altruism is good and violence is generally not. Similarly, God exists regardless of a variation on a gene in my body. Human free will is not negated by genetics. As stated by Nobel Laureate Francis Collins, head of the Human Genome Project: “Heredity does have an influence not only over medical risks but also over certain behaviors and personality traits. But look at identical twins, who have exactly the same DNA but often don't behave alike or think alike. They show the importance of learning and experience—and free will.” [4] Collins plainly stated, “There is no God gene”.

Dean Hamer’s study would be intriguing, if statistically significant and repeatable. However, his findings were not subjected to peer review, have not been replicated, and the conclusion appears to be invalid.

[1] Jeffrey Kluger, “Is God in our Genes?” from TIME Magazine, October 25, 2004.
[2] Dean Hamer, Stella Hu, Victoria Magnuson, Nan Hu, Angela Pattatucci, “A linkage between DNA markers on the X chromosome and male sexual orientation”, Science, Volume 261, No. 5119, July 16, 1993, 321-327.
[3] Carl Zimmer, “Faith-Boosting Genes”, Scientific American, October 2004.
[4] John Horgan interview, “Francis Collins: The Scientist as Believer”, National Geographic, February 2007.