An American molecular geneticist has concluded after comparing more than 2,000 DNA samples that a person's capacity to believe in God is linked to brain chemicals.
His findings have been criticized by leading clerics, who challenge the existence of a "God gene" and say the research undermines a fundamental tenet of faith  that spiritual enlightenment is achieved through divine transformation rather than the brain's electrical impulses.
Dean Hamer, the director of the Gene Structure and Regulation Unit at the National Cancer Institute in Bethesda, asked volunteers 226 questions in order to determine how spiritually connected they felt to the universe.
The higher their score, the greater the person's ability to believe in a greater spiritual force and, Mr. Hamer found, the more likely they were to share the gene VMAT2.
Studies on twins showed that those with this gene, a vesicular monoamine transporter that regulates the flow of mood-altering chemicals in the brain, were more likely to develop a spiritual belief. Growing up in a religious environment was said to have little effect on belief.
Mr. Hamer, who in 1993 claimed to have identified a DNA sequence linked to male homosexuality, said the existence of the "God gene" explained why some people had more aptitude for spirituality than others.
"Buddha, Muhammad and Jesus all shared a series of mystical experiences or alterations in consciousness and thus probably carried the gene," he said. "This means that the tendency to be spiritual is part of genetic makeup. This is not a thing that is strictly handed down from parents to children. It could skip a generation. It's like intelligence."
His findings, published in a book, "The God Gene: How Faith Is Hard-Wired Into Our Genes," are being greeted skeptically by many in the religious establishment.
