Three years ago, the British evolutionary biologist Richard Dawkins became a guinea pig in an experiment. Neuroscientist Michael Persinger claimed he had induced religious experiences in subjects by stimulating specific regions of their brains with electromagnetic pulses. Dawkins, renowned for his biological theories as well as for his criticism of religion, volunteered to test Persinger's electromagnetic device—the "God machine," as some journalists dubbed it. "I've always been curious to know what it would be like to have a mystical experience," Dawkins said shortly before the experiment. Afterward, he admitted on BBC that he was "very disappointed" that he did not experience "communion with the universe" or some other spiritual sensation.
Many researchers, like Persinger, view the brain as the key to understanding religion. Others focus on psychological, genetic, and biochemical origins. The science of religion has historical precedents, with Sigmund Freud and William James addressing the topic early in the last century. Now modern researchers are applying brain scans, genetic probes, and other potent instruments as they attempt to locate the physiological causes of religious experience, characterize its effects, perhaps replicate it, and perhaps even begin to explain its abiding influence.