When a committed Christian says he believes in the Second Coming of Christ, he believes it the way he believes that Michael Jordan was a basketball player. When an avowed atheist says there is no such thing as God, she knows it the way that she knows that Elvis was a rock star. According to new research—published yesterday in the online science journal PLoS One—by Sam Harris (the neuroscientist and atheist author of The End of Faith) and colleagues, "belief is belief is belief," as Harris puts it. "We seem to be doing the same thing when we accept a proposition about God or the virgin birth as we do about astronomy."

What Harris, his fellow researcher Jonas Kaplan, and the other authors of the study want to address is the idea, which has been floating around in both scientific and religious circles, that our brains are doing something special when we believe in God—that religious belief is, neurologically speaking, an entirely different process from believing in things that are empirically and verifiably true (things that Harris endearingly refers to as "tables and chairs"). He says his results "cut against the quite prevalent notion that there's something else entirely going on in the case of religious belief." Our believing brains make no qualitative distinctions between the kinds of things you learn in a math textbook and the kinds of things you learn in Sunday school. Though the existence of God will never be proved—or disproved—by an fMRI scan, science can study a thing or two about the neurological mechanisms of belief. What Harris's study shows is that when a conservative Christian says he believes in the Second Coming as an undeniable fact, he isn't lying or exaggerating or employing any other rhetorical maneuver. If a believer's brain regards the Second Coming the way it does every other fact, then debates about the veracity of faith would seem—to the committed believer, at least—to be rather pointless.

Harris, Kaplan, et al. put 30 people in fMRI machines. Half of them were committed Christian believers, the kind of Christians who would immediately agree with the statement "Jesus ascended to heaven and is seated at the right hand of God the Father." Half were committed atheists, the kind who would agree with the statement "The belief that Jesus ascended to heaven is clearly false." Up on a screen before them, participants would read declarative statements. Some were statements of religious belief, some of religious disbelief. Some were statements about more ordinary facts. Participants had to push buttons—indicating true or false—as the researchers watched their brains light up. Belief in God, disbelief in God, and belief in simple empirically verifiable facts all lit up the ventromedial prefrontal cortex, the area of the brain that governs your sense of self. We are, in some sense, what we believe.

The bigger picture, from Harris's point of view, is that science urgently needs to get involved in the biggest questions of human existence—good, evil, morality, ethics, and what he calls "human well-being"—and not cede these to the religious sphere. "It is generally imagined," he wrote to me in an e-mail, "that scientific facts and human values represent distinct and incommensurable ways of speaking about the world. Consequently, most people assume that science will never be in a position to resolve ethical questions or to determine how human beings ought to live." Questions of gay marriage, the subjugation of women under the Taliban, a community's responsibility to its children: all these have been relegated to the realm of religion or "values." But, says Harris, the more we know, through science, about how people live—and how they think, and what makes them happy—the more real information we'll have about how best to live together on this planet. The fMRI experiments do not pertain to these largest questions, of course. But they do show (again) what neuroscientists already know. "Intuition" and "reason" are not two separate activities. They're interconnected. From the brain's point of view, religious belief and empirical data are the same.

As a student of the faith-versus-reason debate, I find another aspect of these experiments more provocative. Harris proves what is self-evident from observing countless faith-versus-reason debates: each side believes firmly in its own truth claims; each side believes that the other's truth claims are absurd. If Harris is saying that Christians and atheists regard their beliefs the same way they regard uncontested facts ("tables and chairs"), it's no wonder that few conceptual bridges are ever built or crossed. (He even noted, with asterisks as to its significance, what he called the "blasphemy reaction": that when atheists disagreed with a Christian belief, or when Christians affirmed one, their pleasure centers lit up—proof that the combatants in the faith-versus-reason wars really do enjoy the fight, equally.)

But for those of us who yearn for resolution, Harris's experiments offer a glimmer of hope. While the brains of believers and nonbelievers do not differentiate between beliefs about God and about mathematics, the believers themselves do, a little. Participants retrieved their religious beliefs and their historical facts from the same place and in the same way, but they showed less certainty when thinking about the religious statements. It took them a little longer to push the button, and a part of the brain having to do with uncertainty, or cognitive dissonance, lit up. If even the strongest believers are a little unsure about God, and the strongest atheists are a teeny bit anxious that they might be wrong, there's room, perhaps, for one person to begin to try to imagine the world view of another, no matter what the brain sees as true.

© 2009