Here is an article from Scientific American that correlates critical thinking ability to religious belief.
While I do think (and other studies have shown) that a person's knowledge of science, and their ability to think critically is proportional to their belief in unproven claims, I don't think this study was particularly strong. Still it's worth a read for no other reason that it conforms to my belief system. ;-)
Analytic thinking can undermine belief
I'll be back reading the damn book this week. The Gospel of John should be interesting because it's based on hearsay, based on hearsay. At least that's what I heard.