A couple of people pointed me to a recent study by sociologists Dalton Conley and Emily Rauscher that reported that respondents to the 1994 General Social Survey who had daughters were more likely to identify with the Republican Party, compared to parents of sons.

An earlier version of the Conley and Rauscher study appeared a few years ago. And a couple of years before that, economists Andrew Oswald and Nattavudh Powdthavee published a paper with the exact opposite finding:

We [Oswald and Powdthavee] document evidence that having daughters leads people to be more sympathetic to left-wing parties. Giving birth to sons, by contrast, seems to make people more likely to vote for a right-wing party. Our data, which are primarily from Great Britain, are longitudinal. We also report corroborative results for a German panel.

This is a fun problem: we have two different studies, both by reputable researchers, with opposite results! I took a look at both papers and can’t immediately see a resolution, but I will offer some speculation, followed by some scattered comments.

We already know that the Republicans are the party of families much more than Democrats are. Just for example, John McCain did 20 percentage points better among married than unmarried voters.

The way I’d interpret Conley and Rauscher’s finding is that having a child is likely to make you much more focused on family issues, and that having a daughter (as compared to a son) might make this effect even larger. To the extent that the Republicans were seen (as of 1994) as the family-values party, this could swing some votes (or, at least, some party identification). A few years ago, I wrote that it should be possible to look into this by studying GSS responses to some different survey questions. Conley and Rauscher seem to have done some of this in the recent paper, but with no clear results (which makes sense to me, given that any real effects are likely to be small). And, as the above image of four generations of mothers and daughters indicates, these patterns could also be different for people of different ages and different cohorts.

At least in the U.S. context, it makes much more sense to me to see this sons/daughters thing as being a spinoff from the huge differences between married and unmarried voters than in terms of evolutionary strategies (more on this below).

How did the two studies end up with opposite findings? My guess is that, to the extent that these findings are real (rather than mere chance patterns that the different researchers happened to notice in data), it’s differences between different countries. Conley and Rauscher suggest that the difference can be explained by choices regarding the inclusion or exclusion of adopted children or children who are no longer living at home, but both of the articles consider various alternative specifications and the results don’t change much, so I doubt this is what’s going on.

Perhaps unsurprisingly, Oswald and Powdthavee, being economists, focus on economic issues:

The interesting recent work of Campbell (2004) documents systematic gender differences in modern British political attitudes. The author tabulates answers given in the British Election Survey of 2001. She shows that the single most important concern to males is that of low taxes. For females, by contrast, it is the quality of the National Health Service.

Similarly, left-wing parties tend to be more supportive of women-friendly policies such as family leave; and right-wing parties tend to favor increased spending on the military, which is of course mostly staffed by men.

Conley and Rauscher, being sociologists, center their story on social issues:

Males’ optimal reproductive strategy is to sire many offspring with a range of mates and push the parenting requirements onto the mothers. Meanwhile, the mother seeks to maximize not only the genetic fitness of the sire, but also to induce more post-conception investment in rearing the offspring from the father. Seen in this light, more conservative policies that increase the cost of promiscuity–particularly for males–will enhance the reproductive bargaining power of women. . . . The conservative emphasis on family, traditional values and gender roles, and prolife/anti-abortion sentiments all stress investment in children – for both men and women. Conservative policies mirror the genetic interests of women, writ large. They attempt to promote paternal investment in offspring.

To me, this seems to be a lot to hang on a fragile thread. When it comes to economic policy, Democrats are pushing higher taxes and public services while Republicans want lower taxes and public services — and I don’t see how these map at all onto Conley and Rauscher’s categories. Even when you come to the particular issue of abortion, I don’t see how how an antiabortion policy is an “attempt to promote paternal investment in offspring.” There are some deadbeat-dad laws out there, but I didn’t think of them as being associated more with one party than the other.

In summary, I think the patterns found by both sets of researchers are interesting, and I do think it’s reasonable to consider the sex of one’s child as a randomly-assigned treatment. But, multiple comparisons issues do arise, and the existence of two published results in the exact opposite direction suggest, at the very least, that any effects are likely to be lower than claimed in the published articles. As always, multiple comparisons problems are all over the place here — the Conley and Rauscher paper also had some “the difference between significant and non-significant is not itself statistically significant” moments — and I think reporters should be careful before taking the claims based on this sample and assuming that they apply to the population.

The sex of your children is going to have all sorts of effects on your behavior and attitudes. With so many possible outcome measurements and various small effects in different directions, we can’t expect a sample size of 600 or 1,000 to form a coherent story, and I think there is a problem in that the conventions of scientific research papers, and of journalism, are that all the results should cohere.

Finally, I agree with blogger Echidne that the evolutionary psychology speculations in Conley and Rauscher’s paper are incoherent. I won’t go into all the details, but the short version is that when you apply evolutionary psychology to public opinion, you can get the theory to predict just about anything you want. Echidne points out that “the results of Conley and Rauscher are the opposite of their predictions.” If so, how is it that the reviewers of the paper did not notice? I think it’s because the predictions from this sort of theory are so flexible, that anything can be considered as a confirmation.

One more thing

Finally, I think there’s something oddly asymmetrical about how these results are presented, both by the authors and in the media. Consider the following headlines:

“The Effect of Daughters on Partisanship and Social Attitudes Toward Women”

“Does Having Daughters Make You More Republican?”

“Parents With Daughters Are More Likely To Be Republicans, Says New Study”

“Parents Of Daughters Lean Republican, Study Shows”

“The Daughter Theory: Does raising girls make parents conservative?”

To their credit, the study’s authors and many of the journalists make it clear the the claims are speculative (consider, for example, the question mark at the end of the New York Times headline given just above). So that’s all good.

But here’s my question: Why is it all about “the effect of daughters”? Why not “Does having sons make you support the Democrats?” It looks to me like having sons is considered the default. Okay, sure, a bit over 51 percent of babies are boys. Really, though, you can have a boy or a girl, and I think the whole discussion of these claims in the media is a bit distorted by the implicit attitude that the boy is a default. Lots of discussion about how you, as a parent, might change your views of the world if you have a girl. But not so much about how you might change your views if you have a boy. Lots of discussion of how having a girl might affect your attitudes on abortion, not so much discussion about how having a boy might affect your attitudes on issues such as gun control or war, which disproportionately affect young men. This is a real problem, when issues of girls and boys, men and women, are treated asymmetrically.