Responding to Bryan Caplan has become part of my daily routine. In today’s episode, we’re talking about chapter 4 of my recent book with Rob Kurzban.

In that chapter, we discuss our work on how differences in sexual and family patterns relate to differences in religiosity and in sexual and family morals and politics. This is something we’ve been working on for a while now, including my dissertation on abortion attitudes, some material in Rob’s first book, and a series of journal articles on religion and on drug attitudes.

In the book, as Caplan says in his post today, Kurzban and I use the terms Freewheelers and Ring-Bearers to describe different broad lifestyle patterns. Freewheelers sleep around more, party more, get and stay married less, have fewer kids, and so on. Ring-Bearers go in a more traditional direction. We show that these kinds of lifestyle differences really do predict average differences in the public’s views on political and moral topics relating to premarital sex, pornography, abortion, birth control, and marijuana legalization.

Caplan doesn’t dispute our data. Instead, at issue is whether these political and moral differences count as self-interest. Kurzban and I argue that it’s self-interest when people who party and sleep around tend not to want others imposing higher social and legal costs on people who party and sleep around. We argue that it’s self-interest when people who want to sleep around while delaying having children tend to defend access to family planning. We argue that it’s self-interest when Ring-Bearers, whose own lives can be more substantially disrupted by Freewheeler behaviors, tend to seek to reduce those behaviors by making them more costly.

I’ve found that many people (from internet commenters to the op-ed board of a major newspaper) find this all rather “obvious” once it’s laid out. But not Caplan — he thinks it’s “bizarre.”

Of despots and ordinary folks

His main argument is about how it would really be better for any given promiscuous man to be the only promiscuous man. If it were just self-interest, each man would seek to minimize the promiscuity of other men while maximizing his own. Indeed, there’s a long line of evolutionary research showing something along these lines — when individual men achieve despotic power, in fact they often do impose rules that give themselves sexual access to lots and lots of women while imposing very strict limits on other men.

But the thing is that almost no one is a despot. Even in pretty small ponds, very few people are big enough fishes to set such one-sided rules. For ordinary folks, as we explain in our book, announcing to others that you think they should be punished for some behavior in fact makes it more likely others will increase their punishments if you engage in that behavior. Hypocrisy carries added costs. Ordinary folks can’t really have it both ways when it comes to setting general moral rules.

So, yes, I agree that individual men might want to be the only Freewheeler man. The problem is that that’s not usually a live alternative.

What’s self-interest got to do with it?

So let’s assume that people — for whatever reason — differ in their tendencies to lean in a Freewheeler or a Ring-Bearer direction. And let’s assume that, for most people, attempting to impose moral and legal punishment on others for Freewheeler behaviors makes it more likely others would increase punishment for the moralizer for those same behaviors.

The central issue then is whether or not we should expect self-interested Freewheelers to be more likely to support liberal lifestyle policies than self-interested Ring-Bearers.

Caplan says that, because each Freewheeler man wants to be the only Freewheeler man (surrounded by lots of Freewheeler women), our point is defeated. In fact, his argument misses the point. We’re comparing Freewheelers and Ring-Bearers (in a population where almost no one gets to set despotic rules). On average, if a man leans Freewheeler, it’s clear that, on balance, he has more incentives to support general rules lowering costs on Freewheeling than does a man who leans Ring-Bearer. Caplan may think it’s a close call for lots of Freewheeler men, but even if this were true (and I don’t think it usually is), this wouldn’t mean that Freewheeler men have the same average incentives as Ring-Bearer men. Caplan calls this a just-so story, but usually in social science we call it a theory. And, in this case, it’s a theory that is consistent with the data.

Hypocritical spouses

Caplan’s parting shot at undermining our argument is about how Ring-Bearers would be better off under liberal lifestyle rules because it helps distinguish between honest Ring-Bearers and Freewheelers-in-Ring-Bearer’s-clothing. Caplan and I presumably agree that Ring-Bearers usually benefit from others behaving like Ring-Bearers. But Caplan’s argument adopts a sort of fatalistic view of lifestyle behavior, as though there are no incentives that could make someone behave more like a Ring-Bearer or less like a Ring-Bearer.

My view is that incentives matter. If people adopt general societal rules that make Freewheeling more costly, fewer people will engage in Freewheeling behaviors. Further, as Kurzban and I discuss in the book, when religious conservatives loudly announce their support for punishing these behaviors, and embed themselves deeply within social networks that share this punitive attitude, their own incentives not to stray are tangibly increased.

There’s no great puzzle here. Ring-Bearers often want to minimize Freewheeling. So they tend to support conservative lifestyle policies that increase the costs of Freewheeling. The people on whom these costs are placed tend to oppose such costs. There are other details of course — there always are — but the core idea is pretty simple, and I don’t see anything that threatens it in Caplan’s arguments.

Caplan accuses Kurzban and me of bending over backwards to make our theory fit the data, but I think this is another one of those cases where Caplan doth protest too much. After all, he’s defending a view that says, despite self-interest mattering in lots of ways in human life, one of the big areas where self-interest doesn’t matter is (of all things) politics.