Have you ever wondered why religions are more numerous in the tropics than in temperate regions? I'm guessing not, but I'd hate to underestimate you. Either way, we have an answer for you.

A paper written by Corey Fincher and Randy Thornhill of New Mexico University, and published by the Royal Society, argues that the greater the variety of diseases in a place, the greater the variety of religions.

The further you get from the equator, the more ...