In a recently discovered blog, 3quarksdaily, one of the authors posts on new theories that seek to explain religiosity. It's a rather long piece, so be patient. By way of trying to understand religiosity, the author Abbas Raza asks a perfectly good question:
If it [belief] is so irrational, then why is religious conviction so widespread?
He lists two common explanations for belief, one an ethical complaint -- it's a craven escape from reality -- and the second, more straightforward: through ritual, society obtains a benefit. Happy people live longer.
Raza then points to recent research by Pascal Boyer and Paul Bloom that offers a third, and surprising, reason for the widespread belief in belief. Some research now seems to demonstrate that we're born dualists with an early hardwired attraction to "things with minds."
In Paul Bloom's words, children are "natural-born dualists" (in the Cartesian sense). It is quite clear that the mental mechanisms that babies use to understand and predict how physical objects will behave are very distinct from the mechanisms they use to understand and predict how psychological agents will behave. This stark separation of the world into minds and non-minds is what, according to Bloom, makes it eventually possible for us to conceive of minds (or souls) without bodies.
Religiosity is explained as a rational process -- dualism -- taken too far.
The new approach to explaining religion that Boyer and Bloom (and Scott Atran and Justin Barrett and Deborah Kelemen and others) represent does not see religious belief as a corruption of rationality, but rather as an over-extension of some of the very mental mechanisms that underlie and make rationality possible.
...Notice that while previously [think Richard Dawkins] most people have proposed that we are dualists because we want to believe in an afterlife, this new approach turns that formulation around: we believe in an afterlife because we are born dualists.