Why are some people more religious than others? Answers to this question often focus on the role of culture or upbringing. While these influences are important, new research suggests that whether we believe may also have to do with how much we rely on intuition versus analytical thinking. In 2011 Amitai Shenhav, David Rand and Joshua Greene of Harvard University published a paper showing that people who have a tendency to rely on their intuition are more likely to believe in God. They also showed that encouraging people to think intuitively increased people’s belief in God. Building on these findings, in a recent paper published in Science, Will Gervais and Ara Norenzayan of the University of British Columbia found that encouraging people to think analytically reduced their tendency to believe in God. Together these findings suggest that belief may at least partly stem from our thinking styles.

Gervais and Norenzayan’s research is based on the idea that we possess two different ways of thinking that are distinct yet related. Understanding these two ways, which are often referred to as System 1 and System 2, may be important for understanding our tendency towards having religious faith. System 1 thinking relies on shortcuts and other rules-of-thumb while System 2 relies on analytic thinking and tends to be slower and require more effort. Solving logical and analytical problems may require that we override our System 1 thinking processes in order to engage System 2. Psychologists have developed a number of clever techniques that encourage us to do this. Using some of these techniques, Gervais and Norenzayan examined whether engaging System 2 leads people away from believing in God and religion.

For example, they had participants view images of artwork that are associated with reflective thinking (Rodin’s The Thinker) or more neutral images (Discobulus of Myron). Participants who viewed The Thinker reported weaker religious beliefs on a subsequent survey. However, Gervais and Norenzayan wondered if showing people artwork might have made the connection between thinking and religion too obvious. In their next two studies, they created a task that more subtly primed analytic thinking. Participants received sets of five randomly arranged words (e.g. “high winds the flies plane”) and were asked to drop one word and rearrange the others in order to create a more meaningful sentence (e.g. “the plane flies high”). Some of their participants were given scrambled sentences containing words associated with analytic thinking (e.g. “analyze,” “reason”) and other participants were given sentences that featured neutral words (e.g. “hammer,” “shoes”). After unscrambling the sentences, participants filled out a survey about their religious beliefs. In both studies, this subtle reminder of analytic thinking caused participants to express less belief in God and religion. The researchers found no relationship between participants’ prior religious beliefs and their performance in the study. Analytic thinking reduced religious belief regardless of how religious people were to begin with.

In a final study, Gervais and Norenzayan used an even more subtle way of activating analytic thinking: by having participants fill out a survey measuring their religious beliefs that was printed in either clear font or font that was difficult to read. Prior research has shown that difficult-to-read font promotes analytic thinking by forcing participants to slow down and think more carefully about the meaning of what they are reading. The researchers found that participants who filled out a survey that was printed in unclear font expressed less belief as compared to those who filled out the same survey in the clear font.

These studies demonstrate yet another way in which our thinking tendencies, many of which may be innate, have contributed to religious faith. It may also help explain why the vast majority of Americans tend to believe in God. Since System 2 thinking requires a lot of effort, the majority of us tend to rely on our System 1 thinking processes when possible. Evidence suggests that the majority of us are more prone to believing than being skeptical. According to a 2005 poll by Gallup, 3 out of every 4 Americans hold at least one belief in the paranormal. The most popular of these beliefs are extrasensory perception (ESP), haunted houses, and ghosts. In addition, the results help explain why some of us are more prone to believe that others. Previous research has found that people differ in their tendency to see intentions and causes in the world. These differences in thinking styles could help explain why some of us are more likely to become believers.

Why and how might analytic thinking reduce religious belief? Although more research is needed to answer this question, Gervais and Norenzayan speculate on a few possibilities. For example, analytic thinking may inhibit our natural intuition to believe in supernatural agents that influence the world. Alternatively, analytic thinking may simply cause us to override our intuition to believe and pay less attention to it. It’s important to note that across studies, participants ranged widely in their religious affiliation, gender, and race. None of these variables were found to significantly relate to people’s behavior in the studies.

Gervais and Norenzayan point out that analytic thinking is just one reason out of many why people may or may not hold religious beliefs. In addition, these findings do not say anything about the inherent value or truth of religious beliefs—they simply speak to the psychology of when and why we are prone to believe. Most importantly, they provide evidence that rather than being static, our beliefs can change drastically from situation to situation, without us knowing exactly why.

Are you a scientist who specializes in neuroscience, cognitive science, or psychology? And have you read a recent peer-reviewed paper that you would like to write about? Please send suggestions to Mind Matters editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe. He can be reached at garethideas AT gmail.com or Twitter @garethideas.