Religion and Crime
I've been reading the literature on the relationship between religious conviction and crime, as part of my thinking about the relationship between philosophical moral reflection and actual moral behavior. The literature is pretty weak. Much seems church-inspired and probably deserves about the same level of credence as drug-company funded research showing their blockbuster drugs are wonderful. Much of it is in weird journals.
I found a 2001 "meta-analysis" (Baier & Wright) of the literature that shows all the usual blindnesses of meta-analyses. Oh, you don't know what a meta-analysis is? As usually practiced, it's a way of doing math instead of thinking. First, you find all the published experiments pertinent to Hypothesis X (e.g., "religious people commit fewer crimes"). Then you combine the data using (depending on your taste) either simplistic or suspiciously fancy (and hidden-assumption-ridden) statistical tools. Finally -- voila! -- you announce the real size of the effect. So, for example, Baier and Wright find that the "median effect size" of religion on criminality is r = -.11!
What does this mean? Does being religious make you less likely to engage in criminal activity? Despite the a priori plausibility of that idea, I draw a negative conclusion.
First: A "median effect size" of religion on criminality of r = -.11 means that half the published studies found a correlation close to zero.
Second: And that's half the published studies. It's generally acknowledged in psychology that most studies that find no effect -- especially smaller studies -- languish in file drawers without ever getting published. Robert Rosenthal, the dean of meta-analysis, suggests assuming for every published study at least five unpublished studies averaging a null result.
Third: As Baier & Wright note (without sufficient suspicion), the studies finding large effects tend to be in the smaller studies and the studies co-ordinated through religious organizations. Hm!
Fourth: The studies are correlational, not causal. Even if there is some weak relationship between religiosity and lack of criminality, some common-cause explanation (e.g., a tendency toward social conformity) can't be ruled out. Interestingly, two recent studies that tried to get at the causal structure through temporal analyses didn't confirm the religion-prevents-criminality hypothesis. Heaton (2006) found no decrease in crime after the Easter holiday. And Eshuys & Smallbone (2006) found, to their surprise, that sex offenders who were religious in their youth had more and younger victims than those who were comparatively less religious.
Does this suggest that religion is morally inert? Well, another possibility is that religion has effects that go in both directions -- some people using it as a vehicle for love and good, others as a vehicle for hate and evil. (Much like secular ethics, now that I think of it!)