the Evil Line

I just finished reading Daniel Dennett's Breaking the Spell, in which he pleads for a more careful scientific study of religion. An article in the Economist looks at just that. The brain scan studies are completely worthless, but I like the game theory approach that looks at group cooperation:

The splendour of a peacock's tail and the throaty roar of a stag really do show which males are fittest, and thus help females choose. Similarly, signs of religious commitment that are hard to fake provide a costly and reliable signal to others in a group that anyone engaging in them is committed to that group. Free-riders, in other words, would not be able to gain the advantages of group membership.

A writeup of a related study, on the ever-present problem of cooperation in the Prisoner's Dilemma, is here.