Tuesday, August 21, 2012

The Science Behind Todd Akin's Gaffe

ResearchBlogging.orgRecently Rep. Todd Akin (R-MO) made a very bad gaffe. It is pretty serious and you might have already heard about it. The quote in question as made during an interview with KTVI on Sunday was:
“If it's a legitimate rape, the female body has ways to try to shut the whole thing down."
Now a lot of people have been very upset about the phrasing of "legitimate rape" and rightfully so (you can already buy "illegitimate rapist" T-shirts). But that's not what I want to write about. I want to talk about the myths regarding pregnancy and rape. There actually is science that has been done specifically on this problem, and as it turns out the opposite is true. Researchers have found that the "per-incident rape-pregnancy rates exceed per-incident consensual pregnancy rates by a sizable margin." (Gottschall & Gottschall, 2003).

The Gottschalls set out to re-evaluate the data gathered by medical and public health professionals regarding the medical and psychological health of rape victims. By carefully screening this data the researchers were able to come up with meaningful comparisons between consensual (albeit unprotected) sex pregnancy rates and rape-pregnancy rates. After adjusting for contraception use the per-incident rate of pregnancy resultant from rape is about 8%. This is compared to the consensual, unprotected intercourse was calculated at 3.1% (Wilcox et al., 2001). But how can we explain that?

One possible explanation is that women, somehow, broadcast their fertility. That is to say that men can tell when women are ovulating, and that this is arousing, and thus triggers the rapist to strike. While there is evidence that men can detect when women are ovulating, I still don't think that fits well here. In general rape is considered a crime of violence not passion. It is about dominance not reproduction. But even still there may be some link between increased arousal and violence in men. A better supported explanation is that of coitus-induced ovulation. This is like what happens in cats; a significant vaginal stimulation triggers ovulation. In fact the very stress of being raped may trigger ovulation. Researchers were able to show that acute stress can trigger ovulation at any point of the menstrual cycle (Tarin et al., 2010).

Certainly more research is to be done on these and other potential mechanisms of this phenomenon. Even still I think it is important for politicians (and all of us) to use the science that is available to us. There is research that we can use to help inform public policy and I feel it is dangerous for us to ignore science.I don't know what this means for Todd Akin (I'm not a political science professor) but hopefully he'll read some science for next time.

Jonathan A. Gottschall, & Tiffani A. Gottschall (2003). Are per-incident rape-pregnancy rates higher than per-incident consensual pregnancy rates? Human Nature, 14 (1), 1-20 DOI: 10.1007/s12110-003-1014-0 
TarĂ­n JJ, Hamatani T, & Cano A (2010). Acute stress may induce ovulation in women. Reproductive biology and endocrinology : RB&E, 8 PMID: 20504303 Wilcox AJ, Dunson DB, Weinberg CR, Trussell 
J, & Baird DD (2001). Likelihood of conception with a single act of intercourse: providing benchmark rates for assessment of post-coital contraceptives. Contraception, 63 (4), 211-5 PMID: 11376648


  1. More magical thinking from the Republicans...

    Rep. Steve King (R-IA) says that he's never heard of a pregnancy resulting from statutory rape or incest...while research estimates that there are 25,000-32,000 pregnancies from rape each year.

    Sources: http://drjengunter.wordpress.com/2012/08/20/did-todd-akin-get-his-misinformation-on-rape-and-pregnancy-from-physicians-for-life/


  2. Mitch your review of current scientific thought is accurate and well presented. Thanks for laying it out so clearly.

    In my view, the issue is not lack of science, nor lack of accessibility to the current scientific thinking. The issue is that a growing part of U.S. society is making a conscious choice to follow a "know nothing" approach to life (including politics).

    It has become come popular and apparently desirable to counter data-based analysis with "just because I believe it is so" thinking, which is held by many to be just as valid as rational logic.

    The view expressed by Akin is not unique to him. It is a widely held belief, actual facts notwithstanding.

  3. Republicans think that, if they believe it, it must be true!

  4. I appreciate the fact that you only partially quoted him. His full quote is as follows:
    “It seems to me, from what I understand from doctors, that’s really rare,” Akin told KTVI-TV. “If it’s a legitimate rape, the female body has ways to try to shut that whole thing down."
    While I certainly disagree with his insinuation while using the term legitimate, he states that his information is backed by science, as you have also stated. I would like to hear from the same doctors he stated he received this information from. Clearly, one is right, and one is wrong. I'm not a scientist, so I have no credible way to know. However, as lazy and irresponsible as it would be to simply accept Rep. Akin at his word, it would be just as irresponsible to do the same with the information you provided. At least with names, we are able to very the information you present as accurate as presented.

    1. As you correctly point out I have given you the names of the scientists, the peer-reviewed journals in which they published their findings, and even links to those documents (although I think one might have to pay to access the full articles). So it is far less irresponsible to trust me. :)

      When you use a phrase like "really rare" it gives you a lot of wiggle room; is eight times out of one hundred rare? Really rare?

      It is possible that Rep. Akin got his information from a source like this: http://www.christianliferesources.com/article/rape-pregnancies-are-rare-461
      But when checking the references you see that the most recent source was from 1981. This is not to say that all stale references are bad, it is just that there has been a lot of science done in the intervening years.

  5. I don't think he got his information from anywhere. I think he just believed it was true and threw it out there, thinking he was playing up to his base and learned that his base wasn't quite as forgiving. After the gaffe look at the company he's keeping as far as the people who agree with him; this isn't even pseudo science, and as you've shown, not close to reality.