Hamer focused on genes associated with neurotransmitters called monoamines. The monoamines, which include serotonin and dopamine, help to regulate mood, among other functions. Psychiatric drugs such as Prozac and Thorazine affect monoamines, as do psychedelic drugs such as LSD, psilocybin, and mescaline, which can produce mystical visions.

Eventually Hamer found a variant, or allele, of a gene called VMAT, that corresponded to higher scores for what he had defined as spirituality. VMAT stands for vesicular monoamine transporter. The gene manufactures a protein that binds monoamines into packages, called vesicles, for transportation between neurons. Hamer calls the VMAT variant "the spiritual allele," or more dramatically, "the God gene" (also the title of his book)—even though according to his own statistics, it accounts for only 1 percent of the variance in the test scores of his subjects. Francis Collins, head of the Human Genome Project and a devout Christian, calls Hamer's claim "wildly overstated."

Rick Strassman has proposed a theory even more reductionist and far-fetched than Hamer's, yet one that has empirical support. Strassman, a psychiatrist in New Mexico, traces spirituality to a single compound, dimethyltryptamine, or DMT. In his book DMT: The Spirit Molecule, Strassman proposes that DMT secreted by our own brains plays a profound role in human consciousness. Specifically, he hypothesizes that endogenous DMT triggers mystical visions, psychotic hallucinations, alien-abduction experiences, near-death experiences, and other exotic cognitive phenomena.


First synthesized by a Canadian chemist in 1931, DMT is the primary active ingredient of ayahuasca, a hallucinogenic tea ingested as a sacrament by Amazonian Indians and by members of two churches in Brazil. (Although DMT is a controlled substance, the U.S. Supreme Court ruled earlier this year that members of a church in New Mexico can ingest ayahuasca for religious purposes.) Pure DMT normally has no effect when consumed orally, because an enzyme in the gut renders it inactive. But in the 1950s Stephen Szara, a Hungarian chemist who later worked for the National Institute on Drug Abuse, discovered that when injected, DMT triggers an extremely powerful hallucinogenic trip lasting less than an hour.

Like the classic psychedelic compounds LSD, mescaline, and psilocybin, DMT resembles neurotransmitters such as serotonin. But what makes DMT unique among the known psychedelics is that trace amounts of it naturally occur in the human body. Scientists first isolated DMT in human blood in 1965, and in 1972 a group led by the Nobel laureate Julius Axelrod of the National Institutes of Health detected the compound in human brain tissue.

These discoveries led to speculation that endogenous DMT—perhaps produced in excess or improperly regulated by the body—contributes to schizophrenia and other mental illnesses. By the early 1980s, the DMT theory of psychosis was largely abandoned when psychedelic research involving humans became too


Courtesy of Cary Wolinski
controversial. But in 1990, arguing that DMT merited further investigation, Strassman obtained permission from federal authorities to inject the drug into human volunteers.

A Zen Buddhist, Strassman was intrigued by the possibility that endogenous DMT plays a role in triggering mystical experiences. He suspected that DMT might be produced in the pineal gland, a minute organ nestled deep in the brain. The pineal gland abounds both in chemical precursors of DMT, such as tryptophan, and in beta-carbolines, the same compounds that render DMT orally active in the South American brew ayahuasca by counteracting the enzyme in the gut that breaks down DMT. From 1990 to 1995, Strassman supervised more than 400 DMT sessions involving 60 volunteers at the University of New Mexico. These were the first sanctioned psychedelic experiments involving human subjects in the United States since the mid-1970s.

To a certain extent, the DMT sessions fulfilled Strassman's expectations. Many of his subjects reported quasi-religious sensations of bliss, ineffability, timelessness, and reconciliation of opposites; a certainty that consciousness continues after death of the body; and contact with "a supremely powerful, wise, and loving presence." Others underwent classic near-death experiences, feeling themselves leaving their bodies and moving through a tunnel toward a radiant light.

Volunteers also reported visions that did not fit neatly into Strassman's scientific or spiritual worldview, however. Forty-seven percent encountered otherworldly beings, variously described as clowns, elves, robots, insects, E.T.-style humanoids, or "entities" that defied description. These bizarre beings were not always friendly. One of Strassman's subjects claimed to have been eaten alive by insectoid creatures. In part out of concern about this negative experience, Strassman discontinued his research.

Science cannot tell us if God exists only in our imaginations or as an entity beyond our comprehension. So why do some scientists continue the search for the roots of religious experience? Shouldn't such claims of oneness with a God be judged by their fruits, rather than their roots, as William James wrote in The Varieties of Religious Experience? Researchers may persist at these efforts because such studies offer the potential to alter our lives. In principle, these findings could lead to methods—call them "mystical technologies"—that reliably induce the state of spiritual insight that Christians call grace and Buddhists, enlightenment. Already Todd Murphy, a neuroscientist who has worked with Persinger, is marketing the "Shakti headset," a stripped-down version of Persinger's God machine, for "consciousness exploration." Electrodes implanted in the brain that electrically stimulate specific regions are now being tested as treatments for depression and other mental illnesses; conceivably this technology also could be used to induce mystical states.

Suppose scientists found a way to give us permanent, blissful, mystical self-transcendence. Would we want that power? Before Timothy Leary touted LSD as a route to profound psychological and spiritual insight, the CIA was studying its potential as a brainwashing agent. Persinger warns that in the wrong hands, a truly precise, powerful God machine, capable of implanting beliefs or signals that seem to come straight from the Almighty, could be the ultimate mind-control device. "Just think of the practical impact," he says. "People will die for this."

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Also, read a book review about environmentalism as a religion.