I didn't miss that clause. Controlling for SES is not trivial. And they only controlled for it at the state level. I'm just saying that the variables they measu

I didn't miss that clause. Controlling for SES is not trivial. And they only controlled for it at the state level. I'm just saying that the variables they measured seem like the kind of ones that are strongly correlated with economic development, so looking for a week association between the variables themselves is like looking for a needle in a haystack. Even if you eliminate 90% of the haystack (i.e. control for most, but not all, of SES effects), finding the needle doesn't get much easier. Or looking at it another way, my point is that since most correlations like this turn out to both have economic development as a common cause rather than being themselves causally related, I require extraordinary evidence to the contrary before I believe it.