Ask 100 people what they get out of religion and you will probably get 100 different answers. Some worship out of habit, others out of fear of death. New experiments offer two surprising reasons people find God: sex and stress relief.
Men and women shown dating profiles of attractive members of the same sex will describe themselves as more religious than people who don't feel as if they have to compete in the attractiveness stakes. Meanwhile, another study finds that thoughts of randomness push people toward God – but only if they can't attribute feelings of stress to some easily defined external factor. Subjects were primed for random thoughts by being exposed to phrases containing words such as "chance", "haphazard" and "random".
"You can become more or less religious depending on the situation," says Ara Norenzayan, a psychologist at the University of British Columbia in Vancouver, Canada, who was not involved in the studies.
Such fickle religious behaviour could be especially important as promiscuous students mature into monogamous adults, says Douglas Kenrick, a psychologist at Arizona State University in Tempe, whose team uncovered the link between mating and religion.
In a previous survey of 22,000 mostly Christian Americans, he and colleague Jason Weeden found a strong correlation between mating behaviour and religiosity. As you might expect, believers were more likely to be married, want to have large families and frown upon cheating and contraception.
To probe the relationship between sex and God more explicitly, Kenrick and colleague Yexin Jessica Li presented hundreds of students at their university with dating profiles of highly attractive men or women, then probed them about their religious beliefs. A control group of 1500 students merely filled out the religion survey.
Men and women who looked at attractive members of the same sex reported stronger religious feelings than those who checked out prospective mates or just filled in the survey. They were more likely to say "I believe in God" and "We'd be better off if religion played a bigger role in people's lives."
"It's an interesting and surprising phenomenon," says Kenrick, who speculates that people ramp up their belief in a system that tends to enforce monogamy when they're confronted with fierce sexual competition. It might have been expected, for example, that people are more religious when they are young, when they have to compete more for sex.
"People actually switch on and off their religious beliefs over their lifetime to fit the current mating context they're in," he adds.
Sexual strife might not be the only reason people dial up and down their belief in God. Another new report pins changes in religious belief on anxiety.
Aaron Kay's team at the University of Waterloo asked 37 undergraduates to his laboratory, he told them, to study the effects of an herbal supplement on colour perception. He told half of them that the supplement had no side effects, the other half that it causes mild anxiety.
Next, he asked participants from both groups to unscramble lists of five words into four-word sentences that primed them for either unpleasant feelings or random behaviour. So the random group might transform "the haphazardly flew for robin" into "the robin flew haphazardly." While the other translates "eat slimy worms for robins" into "robins eat slimy worms."