[There is] evidence that ongoing political debate about marriage creates stress for gay men and lesbians and perpetuates stigmas and prejudice about their communities. This stress can make people physically and psychologically sick, the APA says, calling the link between stress and illness "well established."

I don't doubt that these debates cause stress, but there's something a little odd about the conclusion. If the goal is to reduce stress, and simply debating the issue is the cause of stress, then the remedy ought to be, I suppose, to stop the debate. It's not at all clear that legalizing the practice will end the debates. Indeed, in states where same-sex marriages have been legalized, it's not like opponents haven't just given up and the issue has vanished.

Not only that, but I have a sneaking suspicion that it's not really the stress of the political debate that is driving their position. Suppose that the membership of the APA reviewed the research on polygamy, and found that the debate surrounding this issue caused stress among polygamists, which in turn could make them physically or psychologically ill. Would these worthies similarly vote in favor of legalizing plural marriage? How about incest? If that debate is stressful, would the APA come out in favor? What about other issues that cause people stress? I'm going to go out on a limb and suggest that if it turned out that if there were a debate about pedophilia which caused pedophiles stress, the APA wouldn't resolve to lift the prohibition on the practice.

But let's press on. The second reason the membership voted in favor of the resolution, again according to news sources, is that while the debate is harmful, marriage itself does good; specifically it "does confer the same sense of security, support, and validation" to same-sex couples as to heterosexual ones."

Before continuing, I should probably make my position explicit, since otherwise my remarks might be misinterpreted. I'm in favor of same-sex marriage or, to put it differently, I'm against discriminating against people based on their sexual preference from entering into contracts, including marriage contracts.

But note that the APA here is suggesting that the fact that marriage confers these benefits is why they favor lifting the ban on it. This implies that if same-sex marriage did not have these benefits, they would oppose it. Not only that, but it makes one wonder, again, about others sorts of behavior. Suppose it turned out that inter-racial marriages did not confer "the same sense of security, support, and validation" as other marriages? Would the APA want to ban them? One very much hopes not.

This is the problem with supporting same-sex marriage on the basis of data. By deciding what they believe should be allowed - and what should be prohibited - on the basis of issues such as stress and "validation," the APA is saying that whether we allow people to do what they want depends on whether or not doing so makes them psychologically healthy, as the APA understands and measures it.

This is both dangerous and, in my opinion, the wrong way to decide this issue. Same-sex couples ought to be allowed to marry even if the debate about the topic is stressful and even if the marriages themselves are less satisfying than heterosexual marriages. Same-sex marriage ought to be permitted because the fact that a person wants to have sex with a person who has the same genitals ought not disqualify them from entering into this or any other state-sanctioned contract.

The statement in 2005 by the APA in favor of using evidence to practice clinical psychology seems puzzlingly to those of outside the discipline; what were they doing before? But maybe they got carried away by their newfound respect for data. If we assume that treatment by clinical psychologists has some value in the first place, certainly evidence is useful in determining which treatment to apply. But evidence isn't needed or useful for deciding that discriminating on the basis of sexual preference is wrong. Same-sex marriage shouldn't be legal because it's healthy; same-sex marriage should be legal because it's right.

In closing, I should note that the APA's use of manufactured justifications for a favored position fits well with a large and growing body of research that suggests that in many cases, people come to a moral position and only afterwards seek reasons to justify their judgment. And we shouldn't be surprised if exactly the same findings surrounding a different issue - polygamy, incest, and so on - lead them to precisely the reverse conclusion. Hypocrisy, I understand, is the natural state of the human mind.

Postscript: The title is an homage to Jon Haidt's paper:

Haidt, J. (2001). The emotional dog and its rational tail: A social intuitionist approach to moral judgment. Psychological Review. 108, 814-834.

Copyright Robert Kurzban 2011. All rights reserved. A slightly modified version of this entry is posted at The Evolutionary Psychology Blog.