Rodin’s The Thinker sparks analytical thinking (Image: Nils Jorgensen/Rex Features)

Charles Darwin and Albert Einstein famously did not believe in a supernatural God, and neither do some scientists today. It now appears there may be a good reason for this: thinking analytically dims supernatural beliefs, apparently by opposing the intuitive thought processes that underpin them.

The vast majority of people believe in a supernatural god or gods, says social psychologist Ara Norenzayan of the University of British Columbia in Vancouver, Canada. Yet there are hundreds of thousands of atheists and agnostics who do not. While scientists have begun to study the psychology of belief, we know little about what causes disbelief.

Humans use two separate cognitive systems for processing information: one that is fast, emotional and intuitive, and another that is slower and more analytical.

The first system innately imputes purpose, personality or mental states to objects, leading to supernatural beliefs. People who rely more on intuitive thinking are more likely to be believers, while the more analytical are less likely. This doesn’t necessarily mean analytical thinking causes disbelief, but activating analytical thinking can override the intuitive system – and vice versa. Norenzayan used this to test the causal relationship.


Analytical priming

His student Will Gervais asked 93 university students to rate their own belief in God and other supernatural agents such as angels. Then, several weeks later, they underwent “priming” for analytical thinking – they were asked to unscramble sentences that included words such as “ponder” and “rational”, read text written in hard-to-read fonts, or even just look at a picture of Rodin’s sculpture The Thinker.

Controls were given less analytically charged tasks: looking at Myron’s Discobolus, or The Discus Thrower, unscrambling sentences containing words such as “shoes”, or read text written in easy-to-read fonts.

Norenzayan and Gervais then asked the students to again rate their supernatural beliefs. The students who had been exposed to analytical priming consistently downgraded their belief in the supernatural, regardless of their previous degree of belief. This was also true of 148 adults tested online.

The simplest way to explain these effects, the team conclude, is if intuitive thinking leads to belief, and analytical thinking suppresses or overrides this process. That gives analytical thinking a causal role in disbelief.

“Our results suggest that habitual analytical thinking could be one reason scientists tend to be disbelievers,” notes Norenzayan. It also suggests that – as some religious people fear – exposure to science may erode belief, not just through discoveries such as evolution, but just by promoting analytical thinking.

But before secularists start putting copies of The Thinker in classrooms, Norenzayan warns that it isn’t so simple. “Many things promote religious belief”, such as fear of death, he says. “You can’t turn a devout believer into an atheist just by encouraging analytical thinking. Other factors will sustain belief.”

Journal reference: Science, DOI: 10.1126/science.1215647