Rob Kurzban, Doug Kenrick, and I have a new article that’s now online (though available only to those with university access, at least until it comes out in print), written for The Oxford Handbook of Evolutionary Psychology and Religion (edited by James Liddle and Todd Shackelford). It’s called “The Elephant in the Pews” and provides a summary of our perspective on religiosity in modern developed societies.
The title relates to the fact that, while there are lots of things that correlate with religiosity in modern developed societies—age, cohort, gender, personality features, disease avoidance, views on cooperative morals, and so on—there are two sets of correlates that are much bigger deals than the others. One involves parent-child resemblance and is almost always acknowledged as being a big deal. In short, more-religious adults are substantially more likely than less-religious adults to have had more-religious parents.
But the other very big deal isn’t often recognized as being a very big deal. It’s the elephant in the pews: reproductive strategy. More-religious and less-religious people in modern developed societies have enormous differences in sociosexuality (i.e., how turned on they are by casual sex) and in moral and political views on sexual and reproductive topics (e.g., views on premarital sex, abortion, pornography, divorce, recreational drugs, and birth control). There are also major religious differences in individuals’ own sexual and reproductive lifestyles (e.g., how many sex partners they’ve had, how many children they have, how long they had sex before having children, whether they have married or divorced or live in a nonmarital cohabitation, how much they drink and use recreational drugs, and so on).
These religious differences in reproductive strategy are on average plainly bigger deals than the other commonly discussed demographic and attitudinal differences. For example, there’s a real gender difference in religiosity in America, but it’s a modest difference and is basically mediated (i.e., swamped, overpowered, eliminated) by much larger differences in sociosexuality. In other words, look at men with different sociosexual lifestyles and attitudes, and they differ greatly on average in religiosity; look at women and it’s the same story. But look at men and women with similar lifestyles and attitudes relating to casual sex, and there aren’t sizable gender differences in religiosity. Or, to take another example, there are real personality differences in religiosity in America (religious folks tend to be more agreeable and conscientious), but, again, these are modest differences and are basically mediated by much larger differences in sociosexuality. Or, to take another example, there is a modest-but-real correlation between religiosity and views on cooperative morals, but this correlation goes away when one controls for the much larger correlate of sexual/reproductive morals.
So reproductive strategy is the elephant in the pews—the thing that often gets ignored as researchers focus on much smaller correlates of religiosity. It’s a simple point, really: Just, you know, look at the effect sizes and mediation patterns. But, as we say in the paper: “while recognizing the elephant in the pews is pretty easy, the harder part is figuring out what it is doing there.”
What’s it doing there?
The real meat of the paper is in our view of the causal links between religiosity and reproductive strategy. To understand where we’re coming from, start with the usual story: The differences you see in adults’ religiosity are mostly the effects of having grown up in more- or less-religious households; these differences in religiosity lead people to have different beliefs about morals, divine rewards and punishments, and so on; and these religious and moral beliefs lead people to live different kinds of lives. So, you know, some people are raised religious; they’re taught about how God thinks promiscuity is bad and wants you to be fruitful and multiply; they end up being religious in the way they were raised and believing the things they were taught; and these beliefs drive their adult behavior, leading them to be less promiscuous and have more kids.
From our perspective, there’s some truth to this story, but also a lot of truth to practically the reverse story: Different people (with different individual features, different ecologies, etc.) end up being differentially attracted to different sexual and reproductive lifestyles; and these lifestyle differences then have a big effect on the morals they choose to endorse, on the religious doctrines they choose to espouse, on whether they seek out or avoid religious groups, and so on. So, you know, some people are raised religious but then nonetheless end up being drawn to sociosexually unrestricted lifestyles (hooking up, partying, shacking up, etc.); as a result of their lifestyle preferences, they stop endorsing moral views that say that hooking up is bad, they stop espousing religious doctrines that claim divine authority for the condemnation of hooking up, and they stop going to church.
Some of our evidence for this view comes from the kinds of statistical mediation patterns I mentioned above. For example, the correlation between religiosity and gender is largely eliminated when you control for sociosexual attitudes and lifestyles. This suggests—though doesn’t necessarily prove—a simple and plausible account: On average, women have more restricted sociosexual orientations than men do, and they end up going to church more than men do because sociosexual orientation is itself a powerful causal factor in determining whether people end up being more or less religious.
Other evidence is in a way more straightforward. I took a direct look at these issues using data from the National Longitudinal Survey of Youth 1997. The basic summary is this. Lots of kids are raised in churchgoing households. But the large majority of these kids end up abandoning it by their mid-20s. In fact, around 75% of those whose parents went to church every week when the kids were teenagers were themselves not attending weekly in their mid-20s. And what predicts which raised-religious kids stuck with it or not? The big predictors were sociosexual ones. Look at how much they party, whether they’re sexually active outside of marriage, whether they’re in a nonmarital cohabitation. This suggests—though, again, doesn’t necessarily prove—a simple and plausible account: Lots of kids are raised religious, but as they enter their teens and 20s many (despite their religious upbringings) become attracted to sociosexually unrestricted lifestyles, and those who do largely end up abandoning regular church attendance because they’re adjusting their religiosity to fit their Sex-and-the-City lifestyles.
Put it all together, and this helps solve one of the great mysteries of religiosity in modern developed societies. People with more kids go to church more, which means that each generation of young people is on average raised in more-religious households than the society as a whole. And yet (as I blogged about recently), in the past several decades, each generation actually has ended up being less religious than the generations that came before. If people are just soaking up their parents’ religiosity, how could that be true? The answer is that, while there is clearly an effect of parental religiosity on offspring religiosity, that’s not the end of the story. Another big piece is that adult lifestyles have a causal effect on adult religiosity, and there are other things going on in the modern developed world that are pushing lots of people to prefer unrestricted, lower-fertility lifestyles, and these lifestyle preferences then make religious involvement less appealing.
We’re not taking an extreme position. In fact, in this new paper we’re more explicit than we’ve been before that we think the causal story is complex. There are causal arrows going from childhood religiosity to adult religiosity and doctrinal beliefs, and from adult religiosity and doctrinal beliefs to morals and lifestyles, and from morals to lifestyles, and from lifestyles to morals, and from lifestyles and morals to adult religiosity and doctrinal beliefs. It’s complicated.
We’re careful to say we’re only talking about modern developed societies because it’s not at all clear that the religiosity-as-a-tool-to-advance-restricted-reproductive-strategies point applies either to historical societies or to less-developed modern societies. I also made this point in my blog series about churchgoers being restricted individuals in fast groups. (For those of you who are really digging into this material, note that I did that blog series after the Elephant paper was written, so the new information in those posts isn’t reflected in the paper—though, anticipating those findings, we did include a cautionary footnote about the problem of assuming that sociosexuality and fast/slow life history are going to turn out to be easily mapped on one another.)
But despite the complexity of this stuff, we do think that there’s a concrete core here that has been neglected, and that an evolutionary lens helps bring into focus. Humans generally seek to advance evolutionary salient social goals—gaining resources, forming and maintaining cooperative relationships, seeking status and esteem, finding and retaining mates, raising children, and so on. In doing so, they seek out various tools, including personally advantageous social groups, personally advantageous moral positions, and personally advantageous stories about how their own positions are reasonable and generous and backed by benevolent authority. Religiosity and its related moral and doctrinal pronouncements in some situations play a causal role when it comes to lifestyles, but also—perhaps even more importantly—religion and morals can be social tools that are adopted or abandoned in service of basic real-life goals, essentially reversing the usual causal story.