We’ve reached the final post in this series. In the first one, I noted that evolutionary researchers have made starkly opposing claims about whether religiosity is driven by fast or slow life history. I then covered a big problem with the fast view: It’s based on group-level data, which can’t tell us about individual-level patterns. Then I discussed a big weakness in the slow view: It claims that unrestricted/restricted sociosexuality is a component of fast/slow life history, when in fact these don’t empirically align in the manner claimed.

Now we’re ready for the resolution. The answer is right there in the title.

In yesterday’s post, I discussed two lifestyle factors—a sociosexuality factor and a fast/slow life history factor—in data from two large publicly available datasets (the GSS and the NLSY97). The sociosexuality factor measures primarily whether people have few or lots of sex partners, do little or lots of partying, and have high-commitment or low-commitment relationships. The fast/slow factor measures primarily whether people have early kids or not, lots of or few kids, and little or lots of education.

At the individual level, does church attendance relate primarily to sociosexuality or to fast/slow life history? The unambiguous answer is that individual-level church attendance in the U.S. relates very substantially to sociosexuality, and hardly at all to the overall measure of fast/slow life history. Churchgoers tend strongly to have restricted sociosexual patterns (few partners, little partying, committed relationships) while church-avoiders tend strongly to have unrestricted patterns, and this is happens without much regard for overall fast/slow life history patterns.

When there are individual-level relationships between churchgoing and core fast/slow measures, they’re smaller and inconsistent. For example, in the GSS, having more children moderately correlates with going to church, but having a child early does not. Put those in a multiple regression and the result is that churchgoers tend to have more children but tend not to have started having them at very young ages. This is because there are different life history paths to having lots of children. The sociosexually restricted paths involve stable monogamous relationships that tend to start after teen years but nonetheless lead to high completed fertility. In a related point, while a multiple regression will show churchgoers having more kids, it will also show them having more education.

Thus we have the first part of the conclusion: In the U.S. (and I suspect in other developed counties as well), churchgoers tend strongly to be restricted individuals.

But we’ve also got evidence from group-level studies that churchgoers come from fast groups. Does that pan out with the two-factor approach? Yes. In both the GSS and NLSY97 samples, I created variables contrasting racial/regional groups that have higher and lower average church attendance—it’s basically African Americans and southerners on the high side and northeasterners and whites on the low side. Here, African Americans and southerners do show substantial average differences from northeasterners and whites in early births, fertility, and education, but there aren’t large overall differences in sociosexuality.

Thus we have the second part of the conclusion: In the U.S. (and I suspect this is largely true elsewhere), churchgoers have faster folks in their racial and regional groups.

Taking a step back, here’s what I think is likely true about the big patterns in religiosity. There seems to be a loose societal-level pattern these days where you have poor-fast-restricted-religious societies and rich-slow-unrestricted-secular ones. (There are various exceptions, of course. For example, societies with a history of communism tend to be poorer but less religious, and the U.S. has higher religiosity than its high wealth would suggest.) At the individual level, we have evidence from the U.S. that (1) fast/slow patterns don’t line up with unrestricted/restricted patterns and (2) it’s the unrestricted/restricted patterns that strongly relate to religiosity. I suspect these are more-or-less true in other developed countries, but I don’t think we know that either are true of less developed countries (I’m thinking, for example, about how sexual morals aren’t big individual-level correlates of religiosity in poorer world regions). Also, when it comes to pre-20th century societies, I’m not sure we have more than a vague sense of how the key relationships worked at the group and individual levels—how fast/slow related to unrestricted/restricted and how religiosity related to lifestyles.

Every time I take a close look at religion data, I learn some new wrinkle that lengthens rather than shortens the story. It would be nice if we could have a super-simple account here, but nature is sometimes an asshole and won’t let us have nice things.