Wednesday, 6 August 2008

Religious infections

Question: Why are religions far more numerous in tropical countries than in temperate areas?

For example, the Cote d'Ivoire has 76 religions while Norway has 13; and Brazil has 159 religions while Canada only has 15 - even though in both comparisons the countries are similar in size.

Answer: More religions have emerged and are maintained in the tropics because, through localized coevolutionary races with hosts, infectious diseases select for three anticontagion behaviours: in-group assortative sociality; out-group avoidance; and limited dispersal.

These behaviours, in turn, create intergroup boundaries that effectively fractionate, isolate and diversify an original culture leading to the genesis of two or more groups from one. Religion is one aspect of a group's culture that undergoes this process. As such, religion diversity correlates positively with infectious disease diversity, reflecting an evolutionary history of antagonistic coevolution between parasites and hosts and subsequent religion genesis.

So the next time you get the shits on your holidays in the tropics, you know why you’ll be praying for divine intervention to get better. Now I’m making any of this up am I? No, of course not. Read the full paper here.