Your chance of getting pregnant if raped...

... goes down, compared to other forms of insemination, because "the female body has ways to shut that down." That's according to Missouri Congressman Todd Akin. But this only works, according to him, if the rape is "legitimate." From this we can easily develop a sort of Witch Hunt method to determine if a woman accusing a man of rape was actually, "legitimately" raped or if she's faking it. If she becomes pregnant from the rape, the rape did not happen.

Is this clear?

OK, now that we have that straight, allow me to bring out this one piece of data I thought I'd never have use of. It is a very limited piece of data, not very useful for a large number of reasons. The question at hand can be divided into two parts: 1) What is the chance of a given intromissive internally insemnating sexual event leading to a pregnancy in a woman not on birth control of average fecundity? Then, 2) Does this probability go down, as the good Congresman claims, or does it stay the same.

The answer to the first question is that it is not terribly high. We are not a one-copulation=one baby species. It takes a bunch of tangos to turn out a tyke, on average (but statistics is NOT a birth control method!). As to the second question, it turns out that according to certain data it actually goes up. It is reasonable to suggest that the chance of a single copulation leading to pregnancy if that copulation is rape is about double the overall average. Maybe.

This has been discussed by Thornhill and Palmer, authors of the controversial book "A Natural History of Rape: Biological Bases of Sexual Coercion" and subsequent to the storm of debate that arose from that it has been looked at more carefully and a little bit verified (see this).

I can very easily suggest explanations for this and I can also cast more doubt on the studies. First, the doubt. We have no idea what the actual relationship between having sex and having babies is. One would think we would know, but we don't. Sure, sex leads to babies and all that, but how many sperm, or how many ejaculations, or whatever, does it take before a single sperm is allowed access to the ovum leading to a pregnancy? Scientifically speaking the research needed to answer this question has not been done. There are no controlled studies in which a sufficient sample of subjects across a range of fertilities (and varying in other appropriate factors) repeatedly have sex with everything carefully measured and controlled. Not one study has done this. I don't expect there to be one any time soon. Our estimates of fecundity are based on reported data, vague estimates, and a lot of thumb sucking. So, when we have a couple of rape-related studies that show a higher pregnancy rate than background, unless it was a lot higher, we would need to take that with a grain of salt.

But if there really is a higher chance of pregnancy resulting from rape, this still may not mean much. There are a number of reasons this could happen, some of which are discussed in the above mentioned book. One very distinct possibility is that rapists are selecting victims somehow, perhaps with their Darwinian wiles, as it were, or perhaps for purely random reasons, who are slightly more fecund than the larger sample from which the baseline statistic is calculated. In any case, the difference is not large.

But, there it is also not lower. The chance of pregnancy from what the Good Congressman calls "legitimate rape" ... a term that will surely live in infamy ... is not lower. It might be higher. But it is not lower. The man is an ignorant fool. He is wrong.

Here he is being wrong:

Hattip Kent Jones.

Added: Here's an idea, ask that this dude be relieved of his duties on the House Science and Technology Committee. Which, amazingly, he is on.

More like this

I know I'm supposed to be posting installment three in the work-life balance series - and it's coming tomorrow, I promise - but I was distracted by this post by Isis's new co-blogger. I think there's a relatively strong consensus that this invention is clearly a bit of Technology Gone Bad. In a…
This question is shorthand for a larger and more nuanced set of questions that has emerged over the last 24 hours here and here as people engage in this very interesting and important discussion about rape, especially wartime rape and related post-apocalyptic rape cultures. "The switch" is a term…
Photo credit: AP In light of last week's posts about why human evolution continues, I think it is critical to make concrete the reality of reproductive variance. It seems highly likely now that Jamie Lynn Spears is pregnant again. This might be a moot point if she has an abortion, though now that…
A mini furor erupted this weekend, when republican Senate nominee Todd Akin defended his position of denying abortions even to victims of rape, because in the case of "legitimate rape," women have biological defenses that prevent pregnancy: “First of all, from what I understand from doctors […

And I should add: Yes, the female body does have "ways of shutting that down." It's called abortion. It has probably always been better that men don't know about these things because they'll just try to control them and at the same time claim that there are mysterious natural processes at work. Jeesh.

Well he's a "good Christian" so I'm guessing in his mind a father abusing his daughter, or forcibly having sex with his wife, would not be legitimate rape. What a f$%#tard

By Doug Alder (not verified) on 19 Aug 2012 #permalink

This site uses the concept of "nonforcible rape" as a trope, but the message is pretty strong:

"In some old patriarchal systems, a woman belonged first to her father (or closest living male relative if the father was dead) and then to her husband. The same logic was applied long after women were no longer literally considered property — rape wasn't an offence against the woman, but against the man she "belonged" to. Once married — and in some systems she could be married off without her consent to some old man she despised or had never met — her husband had a legal and "moral" right to her body whether she liked it or not. It gets even creepier when the bride is underage."

By Jaime A. Headden (not verified) on 19 Aug 2012 #permalink

Lots of people will buy any book that tries to explain deviant sex as an adaptation. It satisfies people's desire for porn, while wrapping in in a brown paper bag of science.

By CherryBombSim (not verified) on 19 Aug 2012 #permalink

Hey Greg, that was interesting, and useful right about now. Thanks.

By Katherine Sharpe (not verified) on 19 Aug 2012 #permalink

"Legitimate rape" has got to be the oxymoron of the year.

That said, and notwithstanding the blandishments of the fancy-pants professor blinding us with actual facts, there are a couple of ways that rape would not lead to pregnancy: the victims might be too young or too old to become pregnant.

Sorry, three ways: guys hardly ever get pregnant after being raped.

"blandishments" ... I don't think that word means what you think it means.

I've mentioned this at a couple other blogs. My 10th grade biology teacher told us this in 1972. It is apparently quite an old idea. From a news story this morning:

The legal position that pregnancy disproved a claim of rape appears to have been instituted in the UK sometime in the 13th century. One of the earliest British legal texts, Fleta, has a clause in the first book of the second volume stating that:

If, however, the woman should have conceived at the time alleged in the appeal, it abates, for without a woman’s consent she could not conceive.

The story also mentioned a similar comment in Elements of Medical Jurisprudence, written by Samuel Farr, in 1814.

Calling him an ignorant fool seems rather generous of you. I saw this story hit twitter and I kept looking for the Onion banner.

Is it Boehner who can get him kicked off the science committee? Hope not given Boehner's record of factually-challenged absurdities and conspiracy theories.

By Daniel J. Andrews (not verified) on 20 Aug 2012 #permalink

Dean, I was recently reading "the last duel" about an incident that took place in 1386. Apparently it was strongly believed at that time that a rape would not result in a a pregnancy. This duel was fought because a man's wife was raped. Interestingly having not conceived before, she did have a baby, probably as a result. I wonder if this belief was a social convenience in as much as if a man's wife got raped any subsequent offspring would be considered by society to be the husbands, no questions asked.
I suppose it is reasonable that conservatives would have a grasp on biology that is some 500 years out o date. Pity so many of the electorate are dumb enough not to disqualify such an idiot.

Sailor, exactly. The Gentleman is essentially correct, in the context of the late Middle Ages. These things are taken care of. By women.

The possibility of pregnancy can't go down but it can increase. Really?

By Terry Fleming (not verified) on 20 Aug 2012 #permalink

Akin simply has no curiosity or imagination. No intellectual honesty either. Curiosity would have led him to wonder about rape and conception and find out the answer. Intellectual honesty would have helped him accept that answer.

And supposing I believed in some "shut that down" mechanism. That's where imagination comes into play. I would think to myself: "Couldn't the mechanism by which raped women don't get pregnant be turned into a contraceptive? I wonder if anyone is researching this." Then I would get my hopes of becoming rich by inventing a new contraceptive dashed by finding out there was no such mechanism.

People like Akin don't have a clue because they don't want to have a clue.

Mark, your reference doesn't say what you say it does.

By Stephanie Zvan (not verified) on 23 Aug 2012 #permalink

Yeah, Mark's reference is ultimately one of the references I refer to in my original post and it says what I said it said when I said that the rate was 5%, higher than the baseline. With caveats. See OP.

Mark, I see that your reference is invalid anyway, but regardless, I would be shocked if Mr Akin knows what pubmed is. Seriously. Even "serving" on the science committee, I would love to see his response to the quesion, "What is pubmed?" The question of understanding anything it indexes would be even less likely.

By Mike Schmidt (not verified) on 25 Aug 2012 #permalink

hi everyone i had been married since 3 and half years ago, since then i am trying to conceive. my age is 34 years now, my hormonal reports including FSH,LH,estrogen and thyriod function tests are normal, my diagnostic laproscopy is also normal and my husbands semen analysis is also normal. my serum prolactin levels are normal, but i have got breast tenderness and secretion after ovulation upto my periods. i have underwent three cycles of IUI without any success. now i am worried what to do? please give me possible reasons for this delay and what should be the future course of action. how can i have a baby for my husband that was my question. so a friend introduce me to this native iya basira so i contacted her, after using her herbs she sent, to my believe i was tested pregnant, it was an amazing miracle. when i showed my husband the result i could see the joy in his eyes, thank iya basira once again for your help, may the lord continue to bless you for the fertility help you are giving we women in need, this is her email contact, for you guys that need her help, she is a wonderful mother.

By marie boyden (not verified) on 28 Jan 2017 #permalink