According to the Bible, "doubting" Thomas, who was one of the 12 apostles of Jesus, reacted to reports of the resurrection with disbelief. He required proof, and he was not convinced until his demand to poke his finger into Jesus' wounds for verification was satisfied. After the probing, Jesus said to Thomas, "Because you have seen me, you believe, blessed are they that have not seen and yet have believed." This biblical story captures the essence of a new discovery about religious disbelief published in tomorrow's edition of the journal Science.
Psychologists William Gervais and Ara Norenzayan, at the University of British Columbia in Vancouver, set out to determine whether or not critical thinking promotes religious disbelief. Their cleaver experiments show that this is indeed true, and the results illuminate how our two minds -- one analytical and the other intuitive -- compete in reaching a decision about what we believe.
But before we risk launching off on another crusade of science against religion, a bit of background will be helpful. Pascal Boyer, at the Departments of Psychology and Anthropology at Washington University in St. Louis, argued in an essay published in Nature in 2008 that religious thinking is an inescapable property emerging from the human cognitive system, but that "disbelief is generally the result of deliberate, effortful work against our natural cognitive dispositions." This is why atheists will never predominate, he argues.
Jonathan Evans, at the Centre for Thinking and Language at the University of Plymouth in England, argues that when it comes to belief, we in fact have two minds -- that is, two distinct cognitive systems in our brain that contribute to belief. The first cognitive system is an evolutionarily ancient one, shared with animals, that runs on instinct and intuition. The second cognitive process is an evolutionarily recent invention, unique to humans, that permits abstract reasoning. Somehow, these two minds have to come to terms. In fact, Evans argues, our two minds constantly battle for attention in our decision-making process, and functional brain imaging provides evidence that different regions of our cerebral cortex are involved in either analytical reasoning or intuition.
A prime example of the more ancient cognitive system at work is President George Bush, who famously relied on his "gut instinct" to guide his decision-making process. Albert Einstein, the epitome of rational, analytical thinking, exemplifies the other cognitive system. Both men, incidentally, spoke publicly and frequently of their belief in God, although their religious concepts differed in more fundamental ways than even the Christian and Jewish traditions that separated them. "Science without religion is lame, religion without science is blind," Einstein concluded. In a subtle way, Einstein's pithy remark seems to recognize the internal struggle between reason and intuition that wrestle out our individual beliefs.
All of this is great fodder for philosophers, but how to design a scientific experiment to answer the question, going back to the Apostle Thomas and even earlier, of whether logical thinking and analysis promotes disbelief in religion?
Gervais' and Norenzayan's first experiment tested the idea that analytical thinkers tend to be less religious. They recruited 179 Canadian undergraduates and gave them analytic thinking tests, followed by a survey to gauge their religious disbelief. As expected, the results showed that higher scores in analytical thinking correlated with greater religious disbelief. But this is just a correlation.
To test for a causal relationship between analytical thinking and religious disbelief, the researchers devised four different ways to promote analytic thinking and then surveyed the students to see if their religious disbelief had increased by the interventions that boosted critical thinking. Varieties of these interventions had already been shown in previous psychological studies to elevate critical thinking measurably on tests of reasoning. In one intervention, when people are shown a visual image that suggests critical thinking (for example, Rodin's sculpture "The Thinker," seated head-in-hand, pondering) just before taking a test of analytic reasoning, their performance on the test increases measurably. Subconscious suggestion about thinking apparently gets the cognitive juices flowing and suppresses intuitive processes. The researchers confirmed this effect but also found that the self-reported religious disbelief also increased compared with subjects shown a different image before being tested that did not suggest critical thinking.
The same result was found after boosting critical reasoning in three other ways known to stimulate logical reasoning and improve performance on reasoning tests. This included having subjects rearrange jumbles of words into a meaningful phrase, for example. When the list of words connoted thought (for example, "think, reason, analyze, ponder, rational," as opposed to control lists like "hammer, shoes, jump, retrace, brown"), manipulating the thought-provoking words improved performance on a subsequent analytic thinking task and also increased religious disbelief significantly.
Belief is a fascinating and difficult subject of study for neuroscientists, psychologists, and theologians. These new findings provide new understanding of the different cognitive strategies that are associated with religious belief, but Norenzayan cautions, "Analytic thinking is only one of several factors that contribute to disbelief. Belief and disbelief are complex phenomena that have multiple causes. We have identified just one factor in these studies."
Furthermore, one should not consider either cognitive strategy superior to the other. "Both intuitive and analytic thinking are useful ways of thinking about the world; they both have their costs and benefits," he says.
Terrence Reynolds, professor and chairman of the Department of Theology at Georgetown University, agrees on this point and reminds us that religion is about more than understanding the world: "Religious believers ought not to be in any way unnerved by the findings of science. At the same time, one has to be careful not to engage in reductionist thinking about religion."
"Religion tends to focus on questions of meaning and value, which may not be available through analytic verification processes," he says. "If one won't think beyond that range of inquiry one would be less prone, I suppose, to believe in things one can't see or experience through the senses."
This could be one reason why most scientists (but not all) tend to be disbelievers, Norenzayan says. "I emphasize, one reason, because there could be other explanations, as well. Although analytic thinking is a core part of scientific training, intuitive thinking also plays a very important role, for example in how scientists think of new ideas or connect different ideas together when they get a 'scientific insight.'"
So it would seem that in this case, science and religion are in agreement: analytic thinking promotes religious disbelief. "If one takes notions of God seriously," Reynolds says, "by definition God is a being that transcends the senses. So if one limits one's potential belief to what one can experience with the five senses, then it is very difficult to imagine how one could appropriate a God given those limitations."
On the other hand, even the Apostle Thomas, after all he had been through, needed something he could touch before he could believe.