Engaging in just 1 anti-social behavior does not mean that you have antisocial personality disorder. For that, you would have to engage in at least 3 of them (plus meet some other criteria). So how many of the men in the study engaged in 3 or more of the antisocial behaviors? The authors told us: 3.9%. They also estimated that marriage resulted in a 30% reduction in antisocial behaviors. All of this is tentative and qualified but let's go with it to get a hint about the actual differences between the single and the married men. Solving the equations, I come up with 13 single men with antisocial behavior disorder and 9 married men. That's a difference of 4 men (out of 289 singles and 289 marrieds). That, too, gives you a sense of what is behind the headlines claiming that married men are better men.
What Were the Results for the Divorced Men? What Happened After Age 29?
The results for the divorced men matter because in studies of other implications of marital status, such as health or happiness, divorced people sometimes fare worse than people who have always been single. When that happens, then the risk is not staying single, it is getting married and then unmarried. You can't say that getting married makes your life better if that's only true for people who get married and stay married.
There were only 18 divorced men out of the 289 twin pairs, and the authors coded them as single, rather than analyzing them separately. They also tried leaving them out entirely, and said it made no difference. The divorced men would be worth revisiting in future years, when there are likely to be more of them. The relevant question is: Does the rate of antisocial behavior change when men transition from being married to being divorced, and how does that rate compare to that of the men who stayed single?
We don't know what happens after age 29, because the data collection (as reported in this study) ended at that age. That's important, though. As the authors note, "antisocial behavior is more common in early adulthood." So the highest rate the authors found for either of the groups at any of the ages was 1.48 behaviors. The biggest difference between married and single men was 0.46 behaviors. Looking past age 29, the overall rate is likely to decrease. Perhaps the difference will, too.
In my next post (here it is), I'll address the questions of what these study results really mean, and who is really nicer, married men or single men.
UPDATE: Here's a New York Times column, by Pamela Paul, that includes part of my point.
[Thanks to Natalya, Lauren, and Deb for the heads-up about the reports of this study.]