Frequent churchgoers absorb a lot of lessons about family: Don't covet thy neighbor's wife; go forth and multiply. Overall, they're a fertile, monogamous bunch. But research suggests that religious attendance doesn't only shape family planning preferences. Just as important, it works the other way around: Americans are motivated to attend services predominantly as a strategy to have lots of babies and keep their partners from straying.
Jason Weeden and his collaborators at Arizona State University analyzed a wide swath of data on Americans' demographics, personalities, morals, sexual attitudes, family plans, and religious habits. They found that, on average, having a "low-promiscuity, marriage-centered, heterosexual, high-fertility reproductive strategy" was the primary instigator of regular pew-sitting.
What's the appeal of churchgoing? Most religious groups offer community support, easing the strains of raising a family. They also enforce monogamy within their ranks. So by joining such an assembly, a man interested in becoming a family guy sacrifices sex with his secretary in return for insurance against cuckoldry. And a woman sacrifices sampling better sperm from outside her marriage in return for a reduced risk of being abandoned by her babies' daddy.