Religious polymorphism: blame it on the parastites?

In the book, I blame parasites for pornography, in that we wouldn't need sex if parasites were not driving genetic diversity. But for an interesting twist on this issue, check out this post from the Economist:

Praying for Health: Religious diversity may be caused by disease

And if you are after the paper, it is available here

Assortative sociality, limited dispersal, infectious disease and the genesis of the global pattern of religion diversity

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