Evolution. Morality. Strategy. Security/Cryptography. This hits so many topics of interest, I can't imagine it not being discussed here. Bruce Schneier blogs about his book-in-progress, The Dishonest Minority:
Humans evolved along this path. The basic mechanism can be modeled simply. It is in our collective group interest for everyone to cooperate. It is in any given individual's short-term self interest not to cooperate: to defect, in game theory terms. But if everyone defects, society falls apart. To ensure widespread cooperation and minimal defection, we collectively implement a variety of societal security systems.
I am somewhat reminded of Robin Hanson's Homo Hypocritus writings from the above, although it is not the same. Schneier says that the book is basically a first draft at this point, and might still change quite a bit. Some of the comments focus on whether "dishonest" is actually the best term to use for defecting from social norms.