In 2004, the same geneticist who had earlier discovered a gene linked to male homosexuality found a gene associated with religious belief. The geneticist, Dr. Dean Hammer of the National Cancer Institute, used a 226-question survey to determine a person’s feelings of spirituality, or willingness to believe in supernatural phenomena. He found that those with an inclination for religiosity tended to share a gene called VMAT2. Nicknamed the “god gene”, it purportedly dictates the flow of mood-altering chemicals in the brain, and determines one’s level of belief in religious experiences.

I first accepted this research with a sense of mild dread. I assumed, forgetting that the devoutly religious tend to eschew all scientific or logical prospects, that the religious would respond to this discovery as a palpable sign that God exists. It seemed like a perfect opportunity for classic religious circular logic, the same used to “prove” the significance of the Bible: We know God exists because we believe in him, and we believe in him because he wants us to.

Even Dr. Hammer used this train of thought. In an interview shortly after his discovery became public, he said, “Religious believers can point to the existence of god genes as one more sign of the creator’s ingenuity – a clever way to help humans acknowledge and embrace a divine presence.”

However, the religious community did not embrace Hammer’s findings. Christian reviewers of Hammer’s book on the subject labeled it as bad science, and claimed that he didn’t define …