Last week, the National Marriage Project released a report which showed that women who had a greater number of sexual partners were less likely to be happy in their marriages. For women who had sex only with their future spouse before marriage, more than 50 percent of them reported having high-quality marriages. That was true for slightly more than 40 percent of women who have had sex with five or more partners before their spouse and only slightly more than 20 percent who had ten or more partners before marriage.

As interesting as this study was, for anyone who has looked at this subject before there was nothing surprising here. Studies have shown that the more partners one has before marriage, the more likely one is to be unfaithful in marriage. Others have shown that a high number of sexual partners is correlated with higher levels of depression in women. Is it any wonder that a greater number of sexual partners can lead to higher rates of unhappiness in marriage?

Washington Post columnist Catherine Rampell finds this all pretty surprising:

It might be tempting to interpret the above findings as indicating that "promiscuous" women are doomed to have unhappy marriages. I have serious philosophical issues with that conclusion, but there are methodological problems as well.

Before we get to her “methodological problems,” let’s talk about the “philosophical” ones. Because I’m not sure how you can have philosophical objections to that conclusion if it is supported by the facts. Either women with more partners are likelier to have unhappier marriages or they’re not. Even if the idea somehow offends your sensibilities about what is right or fair, it seems like that conclusion is hard to escape.

As for the methodological ones, Rampell writes, “the authors have not randomly assigned spouses in their study to a given number of previous sexual/cohabitating/marital partners.” This is a somewhat baffling criticism as well. How would it ever be possible to conduct research on the quality of marriage if the requirement for doing so is that spouses are randomly assigned.

The point of research on marital quality-- and I have done a fair amount of this for my book on interfaith marriage-- is that it is self-reported. Researchers ask people how happy they are in their own marriages and then take note of it. There is no outside person sitting in judgment of the partnership you have formed. And by their own measure the women who have had more partners before marriage have rated their own marriages as unhappier. This may irritate the Catherine Rampells of the world, but that’s her problem, not the report’s authors.