According to this paper, published this week in Science, and described in this article from Psychology Today, the answer you give to the following simple maths question is a predictor of whether or not you are likely to be religious:
Q: If a baseball and bat cost $\$110$, and the bat costs $\$100$ more than the ball, how much does the ball cost?
A: If you answered $\$10$ you are inclined to believe in religion. If you answered $\$5$ you are inclined to disbelieve.
According to psychologists William Gervais and Ara Norenzayan, of the University of British Columbia in Vancouver, the theory goes that if you answer $\$10$, your reasoning is more intuitive, whereas if you go for $\$5$, this means you solve problems analytically, rather than going with your instinct.
They predicted that having a more instinctive reasoning system would correlate with being religious, and vice versa, and they conclude decisively “analytic processing is one factor (presumably among several) that promotes religious disbelief.” They do conclude their abstract by saying “Although these findings do not speak directly to conversations about the inherent rationality, value, or truth of religious beliefs, they illuminate one cognitive factor that may influence such discussions” – so don’t worry, that one’s still open. This analysis of the paper, from Science’s news section, does point out that people’s answers to the questionnaire about their religious beliefs may be influenced by the situation they’re in – and in a critical thinking situation, they may rethink their agreement with given statements.
On a side note, it’s nice to see a maths problem used as a predictor of reasoning skills – and the number of people who’ll read articles about this paper and find themselves unexpectedly thinking about a maths problem brings a smile to my face.