Rep. Todd Akin has been slammed from all corners of the blogosphere and media for his comments alleging that pregnancy rarely results from “legitimate rape.” While it’s not clear what Akin meant by “legitimate rape,” one element of the statement that has been repeatedly debunked by multiple media sources is the latter part of Akin’s statement, in which he argues that the female body can “shut down” a pregnancy before it occurs after a rape. Needless to say, no such physical mechanism exists.

It is precisely this scientifically illiterate portion of the statement that has many people wondering, “What was Akin thinking?” And especially given that he apparently plans to stay in the race, that’s a question even more worth asking going forward.

Sarah Kliff at the Washington Post has put together an exhaustive chronology of the “womens’ bodies can stop pregnancy after rape” argument, which she demonstrates was a talking point in use as far back as the 80′s. Ironically enough, it was mocked and derided even then, to the point where the individual who made the argument – a State Representative named Stephen Freind – had to recant. Sound familiar?

However, the argument didn’t die. From Kliff’s article:

The argument was dormant for about a decade, until the late 1990s. That’s when a North Carolina legislator, whom Garance Franke-Ruta points to, extended the argument to question whether there should actually be a rape exception from abortion restrictions, given that ”The facts show that people who are raped – truly raped – the juices don’t flow.”

Arkansas politician Fay Boozman followed up during during his 1998 Senate campaign by arguing that “fear-induced hormonal changes could block a rape victim’s ability to conceive.” Those remarks lead to a backlash when then-Gov. Mike Huckabee tapped Boozman to run the state’s health department.

The fact that former Governor Huckabee has been so willing to accept this argument in the past may explain why he’s defended Akin. Perhaps the most glaring example of this type of argument, though, came from John C. Wilke, the former President of National Right to Life, who wrote both a full-length article arguing this, and devoted a full chapter in his book “Why Can’t We Love Them Both” to the topic. And just like Akin, Wilke’s argument also included an attempt to distinguish between different kinds of rape. From his first article:

First, let’s define the term “rape.” When pro-lifers speak of rape pregnancies, we should commonly use the phrase “forcible rape” or “assault rape,” for that specifies what we’re talking about. Rape can also be statutory. Depending upon your state law, statutory rape can be consensual, but we’re not addressing that here.

A relatively new category is “date rape.” For some reason this is supposed to be different, but, forcible rape is rape, regardless of whether it occurs on a date or behind the bushes. If a college woman is raped on a date, she should undergo a medical examination and treatment, just as she would in the aftermath of an assault rape. It is not a separate category.[...]

How many forcible rapes result in a pregnancy? The numbers claimed have ranged the entire spectrum of possibilities. Some feminists have claimed as high as 5 to 10 percent, which is absurd. One problem has been the lack of available studies and accurate statistics. Often women do not admit to having been raped. On the other hand, it has been known that women, pregnant from consensual intercourse, have later claimed rape. Is it possible to know the actual facts?[...]

There are approximately 100,000,000 females old enough to be at risk for rape in the United States. If we calculate on the basis of 100,000 rapes, that means that one woman in 1,000 is raped each year. If we calculate on the basis of 200,000 rapes, that means that one woman in 500 is raped each year.

Now for the important question. How many rape pregnancies are there? The answer is that, according to statistical reporting, there are no more than one or two pregnancies resultant from every 1,000 forcible rapes.

And from his book’s chapter:

In a healthy, peaceful marriage, the miscarriage rate ranges up to about 15%. In this case, we have incredible emotional trauma. Her body is upset. Even if she conceives, the miscarriage rate is higher than in a more normal pregnancy. If she loses 20% of 600, there are 450 left. Finally, we must factor in one of the most important reasons why a rape victim rarely gets pregnant, and that is psychic trauma. Every woman is aware that stress and emotional factors can alter her menstrual cycle. To get pregnant and stay pregnant, a woman’s body must produce a very sophisticated mix of hormones. Hormone production is controlled by a part of the brain which is easily influenced by emotions. There’s no greater emotional trauma that can be experienced by a woman than an assault rape. This can radically upset her possibility of ovulation, fertilization, implantation and even nurturing of a pregnancy. So what further percentage reduction in pregnancy will this cause? No one really knows, but this factor certainly cuts the last figure by at least 50%, and probably more, leaving a final figure of 225 women pregnant each year, a number that closely matches the 200 found in clinical studies.

This is a clever way to absolve oneself of the problem involved with rape pregnancies by claiming they’re rare. The trouble is, Wilke’s article didn’t rely on any actual, scientifically measured numbers. He was calculating his estimates via the equivalent of doing math on the back of a cocktail napkin, and using some highly dubious assumptions besides.

Actual studies, on the other hand, show that the rate of pregnancy among women who have been raped is just over 6 percent. In fact, one study showed that rape victims were actually twice as likely to get pregnant as women who had had consensual sex, as one-night stands only yielded a pregnancy rate of 3 percent. This suggests that, far from being the statistical rounding error that Wilke and Akin believe it is, pregnancy by virtue of rape is a serious statistical problem, and one that cannot be brushed off as rare.

Nevertheless, Akin’s willingness to accept – uncritically – an unverified argument based largely on amateur math and wishful thinking demonstrates aptly Rush Limbaugh’s point about him: That remaining ensconced in a like-minded enclave of people, of whatever persuasion, will make you believe false and, in some cases, laughable things.