Having found a way to measure self-transcendence, Hamer's next step was to identify candidate genes that might influence people to be spiritual. He started with the observation that certain drugs altered consciousness toward self-transcendence and mysticism. Psilocybin, a hallucinogen derived from mushrooms, is known to induce mystical and sometimes religious states.¹⁰ Certain amphetamines, including ecstasy (3,4-methylenedioxymethamphetamine, MDMA), have well-documented hallucinogenic and mind-expanding properties. Hamer asked: Is there some chemical in the brain that is structurally similar to these drugs and that could endogenously promote transcendent experience?

Mind-altering drugs are thought to work primarily through receptors that bind monoamine ligands in the brain. Hamer looked at factors that would generally influence monoamine function in the drug-free brain, especially in the serotonin, dopamine(Drug information on dopamine), and noradrenaline neurotransmitter systems. After several false starts, Hamer had a chance meeting with George Uhl, MD, PhD, a neurobiologist at the National Institute of Drug Abuse, who studies generic vulnerability to substance abuse. Uhl had found some new variants in a gene called vesicular monoamine transporter 2 (VMAT2). This gene makes a protein for the vesicles that package neurotransmitters in the presynaptic neuron and later release these signaling chemicals into the neuronal synapse. He had sequenced the gene and mapped out a number of variants, including the polymorphism A33050C, located on chromosome 10. (In position 33050 of that chromosome, a person may have either A [adenine] or C [cytosine].) Uhl had shown that the VMAT2 polymorphism was highly associated with other VMAT2 mutations and could be used as a marker for the gene.

The fact that the protein made from the VMAT2 gene was involved in packaging all the monoamine neurotransmitters—Hamer's candidate endogenous molecules for self-transcendence and spirituality—made this gene a particularly attractive target for study. According to Hamer, "VMAT2 controls the flow of monoamines within the brain" and promotes a "higher consciousness."⁶ The packaging vesicles, besides delivering neurotransmitters to the synaptic cleft for signal transduction, protect these molecules from degradation by enzymes, particularly monoamine oxidases, which remove the neurotransmitter once the neuron fires and the signal has been sent.

Using a color-coded fluorescence assay for A33050C and a fast computer, Hamer compared his subjects' genotypes with their test scores on the Cloninger self-transcendence scale. "We hit pay dirt," is how Hamer described the result.

"There was a clear association between the VMAT2 polymorphism and self-transcendence. Individuals with a C in their DNA—on either one chromosome or both—scored significantly higher than those with an A... Somehow, this single-base change was affecting every facet of self-transcendence, from loving nature to loving God, from feeling at one with the universe to being willing to sacrifice for its improvement.
     The VMAT2 gene variant containing a C—or "spiritual allele," as I began to think of it—was present on only 28% of chromosomes, compared with 72% carrying an A. But because both the C/C and the C/A genotypes had increased self-transcendence scores, compared to the A/A genotype, it worked out that 47%... were in the higher spirituality group, as compared with 53% in the lower group. ...While this one gene might not make one a saint, a prophet, or a seer, it was enough to tip the spiritual scales and predispose one toward spirituality (pp 73-74)".

Though Hamer claims that the VMAT2 polymorphism holds the key to understanding spirituality, he never explains why the C/C genotype is better than the A/A genotype in packaging and protecting brain monoamines from enzymatic degradation and other adverse fates.

God's hardwiring not empirically demonstrated
In searching out the God gene, Hamer wanted to know if consciousness can be explained "scientifically."

"By a scientific explanation, I mean one that can be expressed in terms of the basic principles of chemistry and physics. Proponents of this view often are called 'materialists' because they believe that all mental processes can ultimately be accounted for by a few basic physical laws. Most scientists, including myself, are materialists (p 94)."

As a materialist, Hamer must maintain that believing in God involves some kind of brain "wiring." Though the word hardwired appears in the subtitle of The God Gene, near the end of the text he offers this qualification.

"[J]ust because spirituality is partly genetic doesn't mean it is hardwired. Our genes are more like a family recipe handed down by word of mouth than a precise set of instructions that must be followed in exact detail. The final product depends a lot on how you interpret and execute the formula (pp 211-212)."

Hamer's materialism goes off on a curious metaphorical course here, right into the kitchen! In spite of this epigenetic qualification of his genetic theory of spirituality, and his acknowledgment that besides VMAT2 there may be other God genes, Hamer pushes through to his conclusion. We could ask what standard in science is being met here, or, for that matter, what standard in theology?

And then there is this question: However one might be impressed by the correlation between the VMAT2 gene polymorphism and spirituality, a difference in the vesicular covering of monoamine neurotransmitters in the brain seems to be a pretty small variant on which to hang so important and universal a phenomenon as the capacity for spirituality. One wonders how many other theories could have been put forward and how many other experiments could have been performed that would have also yielded "positive" results.

The "bottom up" explanations for religious belief and spirituality offered by neurotheologians and neurogeneticists derive from a science that sees our lives as being largely determined by biological factors. These theories are based on empirical data that have been "stretched" across a discontinuity that still separates the constructs of brain and mind.¹¹ In spite of what some clinicians and theoreticians propose, no one can yet say how the brain—which is necessary for all activity that we recognize as human and is clearly a progenitor of what we call the mind—produces the contents of consciousness,¹² including religious belief.

Acknowledgement: The author thanks David L. Smith, CSSp, PhD. His article on neurotheology cited here was Dr Muller's introduction to the subject, and he drew heavily from it in writing the first section of this article.