Human Nature

Free To Be You and You and Me

Homosexuality, polygamy, and incest.

Read Slate’s legal bloggers’ reactions to the California same-sex marriage ruling on Convictions. Also in Slate, Kenji Yoshino   calls the decision “revolutionary,”  Emily Bazelon  explains why voters might not freak out, and Dahlia Lithwick explores which branch of California’s government has been most “activist.”

It’s that time again: an election year, voters unhappy with the economy, Democrats poised to reclaim the White House. Time for a liberal state Supreme Court to strike down a law against gay marriage and piss people off. In 2004, it was Massachusetts. Now it’s California. Democrats are terrified that the ruling will energize the right and turn the election into a referendum on same-sex unions.

Actually, it could get a lot worse.

Gay marriage isn’t as politically lethal it used to be. Most voters (including me) now supportmarriage or civil unions for same-sex couples, and the percentage favoring marriage has increased significantly over time. Conservatives need to push the debate into kinkier territory.

How? Look at the campaign materials of the groups pushing to constitutionalize California’s gay-marriage ban. “Establishing same-sex ‘marriage’ as a fundamental right will undermine current polygamy laws and create a new legal precedent for ‘anything goes’ forms of marriage,” says a talking-points summary. A flier says liberals want “legal recognition for any combination of relationships involving two, three or more people.” A memo on focus-grouped messagesadvises conservatives to ask: “How do we say ‘no’ to a woman who wants to become the third wife of a polygamist?”

We’ve heard this slippery-slope argument before. Five years ago, Republican Sen. Rick Santorum of Pennsylvania put it this way: “If the Supreme Court says that you have the right to consensual sex within your home, then you have the right to bigamy, you have the right to polygamy, you have the right to incest. …”

I hate to say it, but things are playing out pretty much as Santorum predicted.

It’s not true that there’s been any cultural rush toward these practices. That was always hogwash, since heterosexuality, jealousy, and aversion to immediate-family incest are broadly grounded in human biology. What’s true is that our categorical bans on polygamy and incest, like our bans on homosexuality, are losing their justification.

Two trends are driving this erosion. One is the rise of privacy as a cultural, political, and legal principle. Societies are becoming less able and less willing to forcibly restrict sexual choices. Do what you want, as long as you’re not hurting anybody. No harm, no foul.

Second, the assumed harm of taboo sex practices is being questioned and subjected to scrutiny. And the evidence is looking pretty weak.

First came the studies of gay parenthood. A year and a half ago, Mary Cheney, the vice president’s daughter, announced that she was pregnant and that she and her lesbian partner would raise the child. Conservatives protested, arguing that gay parents are bad for kids. But dozens of studies compiled by the American Psychological Association showed otherwise.

If you analyze the parenting data that’ve been presented by opponents of gay marriage, they actually indicate that men, not homosexuals, are the problem group. Men are overwhelmingly responsible for crime, domestic violence, and sexual abuse. In fact, in some studies, lesbians score better than straight parents on affection, active caretaking, and parenting skills. It isn’t because they’re lesbians. It’s because two moms are better than one.

Which brings us to polygamy. If two moms are better, how about three or four? I’m skeptical, since jealousy is pretty hard to overcome. But if three women can get along that way, are their kids really worse off?

I used to brush off polygamy as an anti-gay scare tactic. But now there’s a real connection: The U.S. Supreme Court’s 2003 ruling in favor of a right to private homosexual conduct encouraged an emerging détentebetween Mormon polygamists and state governments. According to the Washington Post, state officials “offered a deal: Marry however often you want, but don’t marry children.” A spokesman for Utah’s attorney general tells the Post, “We’re not going to prosecute people solely for adult bigamy.”

In other words, polygamy now has the same legal status as homosexuality in most jurisdictions: Your second marriage won’t carry any legal weight, but it’ll be tolerated.

In reality, most polygamist communities are authoritarian and push girls into marriage before they’re old enough. That’s why Texas raided a polygamist compound last month. But the raid has actually clarified the distinction between plural and underage marriage. “This is not about polygamy,” a Texas government spokesman tells the Dallas Morning News. “It is about child sexual abuse and our commitment to protect children.”

Furthermore, the raid—complete with bogus intelligence and an aftermath fiasco—is already doing for polygamy prosecution what the Iraq war has done for invasions: reminding us why it’s better to stay out.

Now comes the third item in Santorum’s axis of evil: incest.

Is incest unnatural? Not exactly. Last month, Science News reported that inbreeding is surprisingly common in nature, apparently for sound Darwinian reasons.

Is it common among humans? Not as a brother-sister arrangement. But millions of people are doing the next-best thing. In a sample of Pakistanis, first-cousin couples accounted for around 60 percent of all marriages. In a sample of Indians, first-cousin couples accounted for one-third of the marriages, and uncle-niece couples accounted for one-fifth.

Do cousin marriages lead to genetic disease? Generally, no. Six years ago, a study by the National Society of Genetic Counselors found that having a child with your first cousin raised the risk of a significant birth defect from about 3 percent to 4 percent to about 4 percent to 7 percent. The authors concluded that this difference wasn’t enough to justify genetic testing of cousin couples, much less bans on cousin marriage.

Is this just a foreign problem? Nope. Charles Darwin, Albert Einstein, and Rudy Giuliani married their cousins. And globalization is bringing Asian practices to the West. In Britain, the challenge is coming from Pakistani immigrants. Next week, the Royal Society of Medicine will discuss genetics in a multiethnic society. A week later, geneticists will hold a forum titled “ Cousin Marriage: A Cause for Concern?” Defenders of the practice are ready. In addition to the data about low probability of birth defects, they note that women are increasingly having babies in their 30s, which multiplies the chance of Down syndrome. Why tolerate one risky choice but not the other?

We’d better start thinking about these questions. Because we’re going to have to answer them.