Religion: Biological Accident, Adaptation — or Both

By Brandon Keim March 09, 2009 | 5:56:12 PM

Whether or not God exists, thinking about Him or Her doesn't require divinely dedicated neurological wiring.

Instead, religious thoughts run on brain systems used to figure out what other people are thinking and feeling.

The findings, based on brain scans of people contemplating God, don't explain whether a propensity for religion is a neurobiological accident. But at least they give researchers a solid framework for exploring the question.

"In a way, this is a very cold look at religious belief," said National Institutes of Health cognitive scientist Jordan Grafman, co-author of a study in the Proceedings of the National Academy of Sciences. "We're only trying to understand where in the brain religious beliefs seem to be modulated."

Though scientific debate about God's existence has transfixed the public, Grafman's findings fit into a lesser known argument over why religion exists.

Some scientists think it's just an accidental byproduct of social cognition. They say humans evolved to imagine what other people are feeling, even people who aren't present — and from there it was a short step to positing supernatural beings.

Others argue that religion is too pervasive to be just a byproduct. Historically, at least, it must have provided believers and their communities some sort of advantage, or else it would have disappeared.

The argument breaks down into the so-called byproduct and adaptation camps. Of course, they might both be right.

"Religious beliefs might have arisen as a byproduct," said Justin Barrett, an Oxford University specialist in the cognitive neuroscience of religion, "but once in place, they're pretty handy."

Grafman started by interviewing 26 people of varying religious sentiments, breaking down their beliefs into three psychological categories: God's perceived level of involvement in the world, God's perceived emotions, and religious knowledge gained through doctrine or experience. Then they submitted statements based on these categories to 40 people hooked to fMRI machines.

Statements based on God's involvement — such as "God protects one's life" or "Life has no higher purpose" — provoked activity in brain regions associated with understanding intent. Statements of God's emotions — such as "God is forgiving" or "the afterlife will be punishing" — stimulated regions responsible for classifying emotions and relating observed actions to oneself. Knowledge-based statements, such as "a source of creation exists" or "religions provide moral guidance," activated linguistic processing centers.

Taken together, the neurological states evoked by the questions are known to cognitive scientists as the Theory of Mind: They underlie our understanding that other people have minds, thoughts and feelings.

The advantages of a Theory of Mind are clear. People who lack one are considered developmentally challenged, even disabled. Anthropologist Scott Atran, a proponent of the byproduct hypothesis, has suggested that it let our ancestors quickly distinguish between friends and enemies. And once humans were able to imagine someone who wasn't physically present, supernatural beliefs soon followed.

But just as a Theory of Mind provided benefits, so might its supernatural byproducts and the religions that grew from them.

Unlike other animals, humans can imagine the future, including their own death. The hope given by religious beliefs to people confronting their own mortality might provide motivation to care for their offspring.

Supernatural beliefs may also have produced group-level advantages that then conferred benefits to individuals.

"You get some selective advantages, such as inter-group cooperation and self-policing morality," said Barrett. "And maybe the entire network of belief practices, and whatever is behind them, gets reinforced."

According to Barrett, religion may even have created a feedback loop, refining the Theory of Mind that produced it.

"It could be that when you're in a religious community, it improves what psychologists call perspective-taking," he said. "Exercising your Theory of Mind could be good for developing it, making your reasoning more robust."

David Sloan Wilson, an evolutionary biologist at Binghamton University, said the findings fit with the idea that religion started as a cognitive byproduct and became a cultural adaptation, but cautioned against over-interpreting them.

"It's tremendous to see religious belief manifested at the neurological level," he said. "But there's a sense that when you bring things down to that level, that trumps other kinds of understanding. That's not true in this case."

Grafman declined to speculate, instead concentrating on what he hopes to achieve with future research: studying other kinds of religions than were represented in his small sample size, and comparing religious cognition to legal and political certainties.

"The differences and nuances between these types of belief systems will be important to understanding the deliberation that goes on," he said.

Grafman also stressed that the study examined only the nature of religion, not the existence of God.

"He, or She, didn't come in for the evaluation," he said.

Citation: "Cognitive and neural foundations of religious belief." By Dimitrios Kapogiannis, Aron Barbey, Michael Su, Giovanna Zamboni, Frank Krueger, and Jordan Grafman. Proceedings of the National Academy of Sciences, Vol. 106, No. 10, March 9, 2009.

Image: Neural activation produced by God's perceived love (left) and anger (right)/PNAS

See Also:

• Thinking About God — or Cops — Makes You Nicer
• Religion From an Evolutionary Perspective