Bobby Jindal, the Republican governor of Louisiana, was named Piyush by his Indian immigrant parents and raised as a Hindu. His conversion to Christianity, he told an interviewer from Christianity Today, took seven years. It began when his grandfather died and he turned to books for insights into the mysteries of life and death—first the Bible, then the writings of C. S. Lewis and Chuck Colson. It culminated when he was in college watching a Christian movie. “When I saw the actor playing Jesus being crucified,” he said, “it hit me that he was on that cross because of Bobby Jindal, my sins. How arrogant for me to do anything but get on my knees and worship him. The most important moment in my life was when I found Jesus Christ.”

Malcolm Little joined the Nation of Islam when he was in prison, changed his name to Malcolm X, eschewed pork and alcohol, and signed on to a theology that identified white-skinned people as the very principle of evil. Twelve years later, on his pilgrimage to Mecca, he embraced a different perspective, which he attested to in a letter that he mailed to his wife, among many others. “I have prayed in the ancient city of Mina and I have prayed on Mt. Arafat,” he wrote. “There were tens of thousands of pilgrims, from all over the world. They were of all colors, from blue-eyed blonds to black-skinned Africans. But we were all participating in the same ritual, displaying a spirit of unity and brotherhood that my experiences in America had led me to believe never could exist between the white and the non-white.

“You may be shocked by these words coming from me,” he continued. “But on this pilgrimage, what I have seen, and experienced, has forced me to re-arrange much of my thought-patterns previously held, and to toss aside some of my previous conclusions.”

Saul of Tarsus was a Hebrew scourge of the early Christians. One day as he was traveling to Damascus, a brilliant light struck him blind as a voice cried out from the sky, “Saul, Saul, why do you persecute me?” He regained his sight three days later, when a Christian named Ananias placed his hands on him, filling him with the Holy Spirit. From then on, he was known as Paul the Apostle.

In The Varieties of Religious Experience, the psychologist and philosopher William James quotes from a Mr. S. H. Hadley’s account of his conversion. It culminated in a “glorious brightness of the noonday sun” shining into his heart. “Old things had passed away,” he said, and “all things had become new.”

Whether incremental like Jindal’s, rational like Malcolm X’s, explosive like Saul’s, or resurrectional like Hadley’s, the experience of religious conversion may be the ultimate example of rewiring.

Conversion isn’t a correction or a tweak—the convert doesn’t simply replace one idea for another or add a new tenet to his catalog of beliefs. It’s the destruction and the reconstitution of a whole way of thinking, feeling, and being, and as often as not it entails ostracism by family, friends, and tribe. The convert becomes a new person and frequently takes on a new name.

All things do become new for the convert, James asserted, in that the human mind is organized by sets of associations. When its central organizing principle is changed, new associations are formed, giving birth to a new subjective self. James cites the philosopher Edwin Starbuck, who argued that conversion is rarely the bolt from the blue that it seems. Most of the spadework, he surmised, has already been done in the subconscious but has been “blocked” because a person’s old ways of thinking and feeling still dominate.

But what about Saul’s or Hadley’s blinding light? Such experiences are not strictly required for the conversion experience, but they do occur.

Using the jargon of his era, James suggests that some of these experiences may be “automatisms”—dramatic uprushings into consciousness “of energies originating in the subliminal parts of the mind.” Others, he suggests, may be epileptic seizures, which are often accompanied by powerful religious feelings. Some may be migraines, which can produce spectacular visual displays. And some, he allows, may have divine origins.

I once experienced the onset of an ophthalmic migraine as I was crossing 57^th Street in Manhattan. It began when I was blinded by what I supposed was a taxi’s headlights. The light faded after a few minutes, but then it resolved into a crystalline structure, which slowly revolved in the left half of my visual field for the better part of an hour. If I had a stronger religious sensibility, I might well have mistaken the experience for a vision.

In his book Hallucinations, neurologist Oliver Sacks describes an even more spectacular migraine-induced apparition, which he experienced as a small child: “I was playing in the garden when a shimmering light appeared to my left, dazzlingly bright,” he writes. “It expanded, becoming an enormous arc, stretching from the ground to the sky, with a sharp, glittering, zigzagging border and brilliant blue and orange colors.”

People who are susceptible to visionary experiences aren’t any saintlier or godlier than those of us who aren’t, but they may have an especially strong proclivity for spirituality. Geneticist Dean Hamer has hypothesized that a so-called God gene exists, specifically VMAT2, which promotes the production of a monoamine neurotransmitter that is involved with the regulation of serotonin, dopamine, and norepinephrine, which in turn are believed to play a role in feelings of transcendence. Having these feelings confers an evolutionary advantage, he argues, in that they feed religion, which in turn breeds optimism. And optimistic people, he concludes, are more likely to reproduce.

Hamer’s theory is controversial and has no bearing on either the existence of God or the question of whether religion is a force for good or ill. But it does shed light on one possible mechanism by which people may come to believe in the supernatural—and on the extent to which we are wired to be rewired.