More on religion and crime: I suspected that the correlation between not having a religion and being arrested might be due to gender: men are both less religious and more criminal than women. But this is what I found:
Percent ever arrested:
No religion 32.5
No religion 11.8
No religion 43.5
No religion 6.5
Even controlling for gender, people with a religion tend to be less criminal. And according to these numbers, religion is more important than race: non-affiliated whites have higher arrest rates than Protestant blacks (both men and women). The numbers, however, do show that race matters. I combined Chinese, Japanese, and Filipino Americans to make a sufficiently large group, and only one out of 55 had ever been arrested: a Catholic Filipino. The 10 Asians with no religion had zero arrests. It's interesting how 82% of this sample of Asians report a religion: clearly Asian Americans are more religious than people in the old country.
By the way, I looked to see why black Catholics are so much more criminal than Protestants. You can see in the numbers above that the difference is concentrated among men. The only factor I could find is that Black Catholics are a significantly younger group: more of them grew up during the era of high crime. I suppose they are younger because as Steve Sailer wrote, more black kids are being sent to parochial schools, and some convert. Steve also thought (as did I) that they might be concentrated in New Orleans, a crime-ridden city. But the largest share of them (according to the GSS) live in the mid-Atlantic division--NJ, NY, and PA.