Who knows? I’m starting to think that the way one answers the question is as close to a Rorschach test as there is in the social sciences. After David Brooks opined that social happiness is more important than material gain (after a certain level of subsistence is attained) and used the example of “successful” marriages to make his point, Andrew Sullivan agreed with him, and Bella DePaulo took exception to Brooks’s conclusions.
It may not have escaped you that reactions fell along predictable lines here. That’s not surprising, because trying to tease out the social benefit of marriage is especially difficult, so that everyone can feel some justification for their conclusions. Even if we try to correct for the selection bias (happier, more successful folks are the ones who tend to marry), in a sense the problem is intractable. We would need to study a control group of Doppelgangers who didn’t have marriage available as an option, and see whether their happiness mirrored that of their real-life counterparts (married and not married). This isn’t likely, except perhaps in a joint venture between the SciFi Network and some dreary public access cable station.
The weight of the social science evidence does suggest that marriage produces social good, but all I’m able to get from that is:
(1) To the extent that marriage leads to longer, happier lives, that’s likely true for gay and lesbian couples as well. (Maggie Gallagher mostly forgets to mention that her co-author on “The Case for Marriage” — Linda Waite, who, unlike Gallagher, is an actual social scientist — favors marriage equality.) We’ll soon have some preliminary data to support that conclusion, but we already know, from one study of couples in Vermont, that those who entered into civil unions stayed together longer than couples who didn’t.
(2) Legal and social support for marriage isn’t justified to the extent that it hoards all of the benefits for married couples and overlooks the needs of other families and living arrangements. Even if some gentle coercion in the direction of marriage is desirable social policy (a highly contestable proposition), that’s no excuse for the embarrassment of government-conferred benefits and riches (to an extent copied by the private sector, as in the case of health benefits) from which other couples are completely excluded.
As James Joyner points out, popularizing social science research may be fun for everyone concerned, but it’s risky business.