US states defending same-sex marriage bans say the ability to procreate naturally dictates wedding rights. This is irrational, says William Saletan

During the US Supreme Court’s oral arguments in Obergefell vs Hodges, a case challenging state gay marriage bans, Justice Ruth Bader Ginsburg raised a good question. What should states that ban same-sex marriage do, she asked, when a 70-year-old straight couple asks for a marriage licence? “You don’t have to ask them any questions,” she , to “know they’re not going to have any children.” If marriage is for procreation – and gay couples are excluded for that reason – why aren’t old couples excluded, too?

The man to whom Ginsburg posed the question – an attorney representing four states that forbid gay marriage – had no good answer.

And his inability to explain the discrepancy cuts to the heart of the issue, because the states whose laws have been challenged in Obergefell – Ohio, Kentucky, Michigan and Tennessee – have staked their case on reproductive biology.

Last autumn, in its ruling on Obergefell, the Sixth Circuit Court of Appeals bought the biology argument. Marriage, the court , is “an incentive for two people who procreate together to stay together for purposes of rearing offspring”. In excluding same-sex couples from this institution, the court concluded, states had simply accepted “the biological reality that couples of the same sex do not have children in the same way as couples of opposite sexes.… That explanation, still relevant today, suffices to allow the states to retain authority over an issue they have regulated from the beginning.”

Reject this argument

Organisations that oppose homosexual behaviour have echoed this argument in briefs to the Supreme Court. “As a matter of simple biology, only sexual relationships between men and women can lead to the birth of children by natural means,” says the .

Many of my friends reject this argument as irrational. . The distinction is solid. It really does exclude all same-sex couples. However, to apply it honestly, you’d also have to exclude . As the Human Rights Campaign in its brief to the court:

“[T]here are at least three different kinds of couples who might qualify for marriage: (1) fertile straight couples, (2) infertile straight couples, and (3) infertile gay couples. Assuming for the sake of argument that the state’s only interest in marriage is to channel ‘responsible procreation’ (which is clearly not the case in any event), it might make sense to draw a line between the first and second groups. But, once the second group is allowed to marry, what sense does it make to draw the line between the second and third groups, who are identically situated for these purposes? After all, it is not as if the second group can ‘responsibly procreate’ any better than the third group.”

This is a serious problem for opponents of gay marriage. They’ve tried to answer it by pleading that infertile straight couples are hard to identify. To find out which couples are infertile, they argue, you’d have to invade everyone’s privacy. The bishops’ brief, quoting a , says states would have to “give sterility tests to all applicants, refusing licences to those found sterile or unwilling to raise a family. Such tests and inquiries would themselves raise serious constitutional questions.” The Family Research Council offers the : “Such an inquiry would be constitutionally barred and impossible to administer.”

Old folks

That’s a decent answer. But it doesn’t apply to the biggest category of infertile people: old folks. A separate brief, filed by a collection of organisations representing senior citizens, . According to , 18 per cent of men and 15 per cent of women who got married in the US in 2009 – more than 700,000 people – were at least 45 years old. More than 250,000 were at least 55 years old. More than 80,000 were at least 65 years old. From 2009 to 2013, the 45-and-over segment of the just-married population increased to 20 per cent of men and 16 per cent of women. That’s more than 750,000 people, “couples in their eighties and nineties”.

Based on these figures, the brief computes that, from a procreative standpoint, banning gay marriage but not elderly marriage isn’t just illogical. On balance, it’s counterproductive:

“Approximately 15 per cent of the marriages entered into each year involve an older couple who are almost certainly incapable of procreation. In contrast, if all legal restrictions are removed, same-sex couples are likely to account for two to four per cent of all marriages. A classification that allows a substantial number of older couples to marry despite being incapable of procreation, while preventing a small minority of older couples from marrying because they are incapable of procreation, clearly does not bear a rational relationship to the goal of restricting marriage to couples capable of procreation.”

That’s a powerful indictment. And the brief goes further. It notes that “a number of states allow otherwise unlawful marriages only if the celebrants are too old (or otherwise unable) to procreate”. Arizona allows first cousins to marry one another only “if both are at least 65 or older, or one is over 65 and the judge receives ‘proof… that one of the cousins is unable to reproduce'”. Illinois requires first cousins to be at least 50 years old or to prove that one of them is “irreversibly sterile”. Wisconsin requires the female cousin to be 55 or older. Indiana and Utah have similar statutes.

Disappearing fertility

Why do states allow cousins to marry at age 50 or 55? Because that’s when a woman no longer has a serious chance at conception. The average age of menopause is 51, and women generally stop bearing children . By age 45, 87 per cent of women are infertile. The median age at onset of sterility is 44.7 years, with a and a . Beyond that, the outliers are in the . The oldest age at which a woman is known to have conceived a successful pregnancy without hormone treatment or donor eggs is .

At age 60 or above, there’s no record of any woman conceiving a successful pregnancy naturally. A few have used . But once you cross that line, you’re doing the same thing lesbian couples can do: using somebody else’s gametes. Opponents of gay marriage don’t accept that kind of procreation as a basis for marriage. As the bishops put it: “Only sexual relationships between men and women can lead to the birth of children by natural means.”

So age 60 clearly demarcates the point beyond which sexual relationships aren’t procreative. The state doesn’t have to ask you any questions or administer any tests. It already knows your age, because you wrote it down when you applied for the marriage licence. Read the at issue in Obergefell. Right below the section that , there’s a section requiring the parties to .

If Ohio and other states want to limit marriage based on procreation, they’ll have to treat age the same way they treat sex. And Ginsburg’s hypothetical cut off – age 70 – is way too lax. Any marriage application on which a woman reports her age as 60 or older would have to be rejected. The Sixth Circuit’s ruling in Obergefell implies that the line should be drawn even earlier, at 50. The judges noted that a prior Supreme Court case holds that a state may require law enforcement officers to retire without exception at age 50, in order to assure the physical fitness of its police force. If a rough correlation between age and strength suffices to uphold exception-free retirement ages (even though some 50-year-olds swim/bike/run triathlons), why doesn’t a correlation between male-female intercourse and procreation suffice to uphold traditional marriage laws (even though some straight couples don’t have kids and many gay couples do)?

Fine. We’ll accept the correlation between male-female intercourse and procreation, if you’ll accept the correlation between age 50 and procreation. Amend your laws to prohibit the marriage of any woman beyond that point. Or extend marriage rights to , whether gay or old.

This article first appeared on

Will Saletan writes about politics, science, technology, and other stuff for Slate. He’s the author of .

Driving into a conspiracy? (Image: REX/Courtesy Everett Collection)

To believe that the US government planned or deliberately allowed the 9/11 attacks, you’d have to posit that President Bush intentionally sacrificed 3,000 Americans. To believe that explosives, not planes, brought down the buildings, you’d have to imagine an operation large enough to plant the devices without anyone getting caught.

To insist that the truth remains hidden, you’d have to assume that everyone who has reviewed the attacks and the events leading up to them – the CIA, the Justice Department, the Federal Aviation Administration, the North American Aerospace Defense Command, the Federal Emergency Management Agency, scientific organisations, peer-reviewed journals, news organisations, the airlines, and local law enforcement agencies in three states – was incompetent, deceived or part of the cover-up.

And yet, as Slate’s Jeremy Stahl , millions of Americans hold these beliefs. In a taken six years ago, only 64 per cent of US adults agreed that the attacks “caught US intelligence and military forces off guard”. More than 30 per cent chose a different conclusion: that “certain elements in the US government knew the attacks were coming but consciously let them proceed for various political, military, and economic motives”, or that these government elements “actively planned or assisted some aspects of the attacks”.

How can this be? How can so many people, in the name of scepticism, promote so many absurdities?

The answer is that people who suspect conspiracies aren’t really sceptics. Like the rest of us, they’re selective doubters. They favour a world view, which they uncritically defend. But their worldview isn’t about God, values, freedom, or equality. It’s about the omnipotence of elites.

Conspiracy chatter was once dismissed as mental illness. But the prevalence of such belief, documented in , has forced scholars to . Conspiracy theory psychology is becoming an with a broader mission: to understand why so many people embrace this way of interpreting history. As you’d expect, distrust turns out to be an important factor. But it’s not the kind of distrust that cultivates critical thinking.

In 1999, a research team headed by Marina Abalakina-Paap, a psychologist at New Mexico State University, published a . The students were asked whether they agreed with statements such as “Underground movements threaten the stability of American society” and “People who see conspiracies behind everything are simply imagining things”. The strongest predictor of general belief in conspiracies, the authors found, was .

But the that was used in the experiment to measure “trust” was more social than intellectual. It asked the students, in various ways, whether they believed that most human beings treat others generously, fairly and sincerely. It measured faith in people, not in propositions. “People low in trust of others are likely to believe that others are colluding against them,” the authors proposed. This sort of distrust, in other words, favours a certain kind of belief. It makes you more susceptible, not less, to claims of conspiracy.

Once you buy into the first conspiracy theory, the next one seems that much more plausible.

A decade later, a study of British adults yielded similar results. Viren Swami of the University of Westminster, working with two colleagues, found that beliefs in a 9/11 conspiracy were associated with . He and his collaborators concluded that “conspiracist ideas are predicted by an alienation from mainstream politics and a questioning of received truths”. But the cynicism scale used in the experiment, drawn from a , featured propositions such as , and It didn’t measure general wariness. It measured negative beliefs about the establishment.

The common thread between distrust and cynicism, as defined in these experiments, is a perception of bad character. More broadly, it’s a tendency to focus on intention and agency, rather than randomness or causal complexity. In extreme form, it can become paranoia. In mild form, it’s a common weakness known as the – ascribing others’ behaviour to personality traits and objectives, forgetting the importance of situational factors and chance. Suspicion, imagination, and fantasy are closely related.

The more you see the world this way – full of malice and planning instead of circumstance and coincidence – the more likely you are to accept conspiracy theories of all kinds. Once you buy into the first theory, with its premises of coordination, efficacy, and secrecy, the next seems that much more plausible.

Many studies and surveys have documented this pattern. Several months ago, asked 1,200 registered US voters about . Fifty-one per cent said a ; only 25 per cent said Lee Harvey Oswald acted alone. Compared with respondents who said Oswald acted alone, those who believed in a larger conspiracy were more likely to embrace other conspiracy theories tested in the poll. They were twice as likely to say that a UFO had crashed in Roswell, New Mexico, in 1947 (32 to 16 per cent) and that the CIA had deliberately spread crack cocaine in US cities (22 to 9 per cent). Conversely, compared with respondents who didn’t believe in the Roswell incident, those who did were far more likely to say that a conspiracy had killed JFK (74 to 41 per cent), that the CIA had distributed crack (27 to 10 per cent), that the government “knowingly allowed” the 9/11 attacks (23 to 7 per cent), and that the government adds fluoride to our water for sinister reasons (23 to 2 per cent).

The appeal of these theories – the simplification of complex events to human agency and evil – overrides not just their cumulative implausibility (which, perversely, becomes cumulative plausibility as you buy into the premise) but also, in many cases, their incompatibility. Consider the in which Gallup asked 471 Americans about JFK’s death. Thirty-seven per cent said the Mafia was involved, 34 per cent said the CIA was involved, 18 per cent blamed vice-president Johnson, 15 per cent blamed the Soviets, and 15 percent blamed the Cubans. If you’re doing the maths, you’ve figured out by now that many respondents named more than one culprit. In fact, 21 per cent blamed two conspiring groups or individuals, and 12 per cent blamed three. The CIA, the Mafia, the Cubans – somehow, they were all in on the plot.

Two years ago, psychologists at the University of Kent led by Michael Wood (who at a delightful ), escalated the challenge. They offered UK college students : four in which she was deliberately killed, and one in which she faked her death. In a second experiment, they brought up two more theories: that Osama Bin Laden was still alive (contrary to reports of his death in a US raid earlier that year) and that, alternatively, he was already dead before the raid. , “The more participants believed that Princess Diana faked her own death, the more they believed that she was murdered”. And “the more participants believed that Osama Bin Laden was already dead when US special forces raided his compound in Pakistan, the more they believed he is still alive”.

Another research group, led by Swami, fabricated conspiracy theories about Red Bull, the energy drink, and showed them to 281 Austrian and German adults. One statement said that a 23-year-old man had died of cerebral haemorrhage caused by the product. Another said the drink’s inventor “pays 10 million euros each year to keep food controllers quiet”. A third claimed, “The extract ‘testiculus taurus’ found in Red Bull has unknown side effects.” Participants were asked to quantify their level of agreement with each theory, ranging from 1 (completely false) to 9 (completely true). The average score across all the theories was 3.5 among men and 3.9 among women. According to the authors, “the strongest predictor of belief in the entirely fictitious conspiracy theory was belief in other real-world conspiracy theories”.

Clearly, susceptibility to conspiracy theories isn’t a matter of objectively evaluating evidence. It’s more about alienation. People who fall for such theories don’t trust the government or the media. They aim their scrutiny at the official narrative, not at the alternative explanations. In this respect, they’re not so different from the rest of us. Psychologists and political scientists have that . Scholars call this pervasive tendency “motivated scepticism”.

Conspiracy believers are the ultimate motivated sceptics. Their curse is that they apply this selective scrutiny not to the left or right, but to the mainstream. They tell themselves that they’re the ones who see the lies, and the rest of us are sheep. But believing that everybody’s lying is just another kind of gullibility.

This article originally appeared in .