Everyone hates adultery

John Sides and Matt Yglesias delve into the General Social Survey to see why people's attitudes toward adultery have changed.

Hester Prynne by Flickr user Billhd

The GSS is great; it may be my favorite dataset of all time. And I remember the first time I sat down and started playing with it I immediately gravitated to the variables about social behavior--extramarital sex, premarital sex, pornography, gay sex, and so on. Political scientists hardly ever get to play with these sorts of variables, and guys who do International Relations absolutely never have time to wonder what causes adultery. And Sides, like Douthat and Yglesias, is right to be shocked at the levels of support for extramarital sex--it is striking the first time you plop these into Stata to see that your parents' or grandparents' generation enjoyed a bit on the side.

Sides observes that more-educated Americans have gotten less accepting of adultery, and speculates that the availability of divorce has something to do with it. Yglesias notes that an alternative theory is that female empowerment has made women less reliant on breadwinners, and so the "marriage market" may have allowed them to find more suitable mates and enforce better behavior by holding out an exit option.

I think these are both plausible theories worth investigating. But I want to add some data and some thoughts to this debate. What follows uses only descriptive statistics (for now), so no interpretation is needed, just some careful thought. But I want to drive down one main point: Adultery used to be at least somewhat popular, but everyone hates adultery more than they used to, and this shift has affected practically all subgroups over the past forty years.

First, let's take a look at some additional data. The two charts below show shifts in opposition to adultery by sex and by race over the period 1972 to 2010.

First, a couple of notes. I follow Sides in defining opposition to adultery (and, yes,  I am using the shorter and judgmental term) by using the GSS question XMARSEX. (By the way, this is how we refer to GSS variables at my department--"XMARSEX," "PORNLAW", "HOMOSEX", etc. Way cooler than standard variable names like "V16".) In this case, I am conservative: Opposition to adultery includes only those who say adultery is always wrong.

Second, we should be aware that the GSS responses constrain our ability to answer these questions. What we want to know is under which circumstances people believe adultery is acceptable, but we merely know if they think it is "almost always" or "sometimes" wrong, or "not wrong at all." It is possible that the categories we're measuring have changed--that the person who thought in 1975 that extramarital sex was almost always wrong would believe that given today's divorce laws that it is now simply wrong to engage in affairs. There are strategies to cope with challenges such as these, but I'm not going to get into them now.

Third, we should always be aware that America has changed a lot in the past 40 years. In 1972, only 11 percent of respondents had a college degree; in 2010, 29 percent of respondents did. Similarly, in 1972, about 84 percent of respondents were white; in 2010, only about 76 percent of respondents were. (That's one reason why I just use "White" and "Black" as categories in the race chart--there aren't enough observations to support finer-grained categories across such a long time period.)

Getting back to the charts with these caveats in mind, though, we can see that the same picture that John held out is broadly true: even groups (like men) that used to be favorable to adultery are no longer supporters. The same pattern can be seen by looking at religious affiliation, which I present in two ways. The first looks at Protestant versus Catholic attitudes and the second at all respondents who view themselves as religious versus those who have no religious preference (e.g., atheists and agnostics). (Again, data limitations prevent me from displaying anything more fine-grained.)

Here we begin to see an interesting pattern. The shift in societal mores has affected even atheists and agnostics, contrary to what we might expect if we get all of our news from Glenn Beck. Secondly, although nonreligious respondents are more tolerant of deviations from marital fidelity, the gap is narrowing quickly; nonreligious respondents are now almost as willing to condemn adultery as Catholic respondents were in 1972.

Just for fun, I also looked at a partisan breakdown.

Although there is a widening split between the parties on this issue (and others), nevertheless Democrats and Republicans alike have grown less tolerant of adultery, at least at a mass level.

Given the relationship of adultery to marriage (long recognized by playwrights among others), we might want to investigate whether those who are married have different ideas than the population as a whole. A plot of opposition to adultery by marital status reveals a surprising pattern. In this case, we see that although married respondents have always been intolerant of adultery, divorced/separated respondents and never-married respondents have quickly caught up.

Note that fewer than half of single respondents in 1972 thought extramarital sex was "always wrong," which explains Mad Men. Very interestingly, in the early 1970s divorced respondents were fairly accepting of extramarital sex, but over the past few years their attitudes have converged on those of married respondents a generation ago. (One wonders if there isn't a natural ceiling to how strongly divorced respondents will condemn adultery, since some of them, at least, are presumably divorced because of an affair.)

Finally, I looked at whether levels of workforce participation by women have tracked with changes in perceptions on adultery. The first chart takes women who are working either full or part-time and compares their attitudes with women who are not (e.g., laid off, never working, retired, and so forth).

Here, we can see that there is support for a modified version of the Yglesias hypothesis. If the effect of women getting jobs is to make them more likely to demand marriage equality and fidelity, than that effect is recent. In the 1970s and 1980s, women who worked approved of adultery at nearly the same rate as men.

 However, there does seem to be some support for the idea that male attitudes have changed. The chart immediately above compares the attitudes of men whose wives work full- or part-time with those of men who are unmarried or whose wives do not work. Whereas there was practically no difference between those two groups throughout the 1970s or even the George H.W. Bush administration, a wide gap opened up during the Clinton-Bush administrations. (It remains to be seen whether the steep decline in 2010 is a blip.) This is consistent with Yglesias' (girlfriend's) hypothesis: male attitudes have shifted faster and more consistently than women's.

Finally, I want to point out that the GSS is sponsored by the National Science Foundation. This is what federal support of social science underwrites. It's critical to have these data in uninterrupted time-series, and it's essential that guys like Tom Coburn not be allowed to take away funding for such projects.