Mike the Mad Biologist

That’s not very civil of me, but it is honest. Having said that, behavior is obviously based in biology, and it does stand to reason that some behaviors will have been influenced by natural selection. Admittedly, I’m biased against evolutionary psychology: I think, in general, the claims made are far too strong and the confounding variables inadequately controlled (in my really snarky moments, I think evol psych is a justification for middle-aged faculty to sleep with their younger graduate students). A recent Slate article which asks “Have women evolved to protect themselves from sexual assault?” The article provides four arguments that women have evolved anti-rape defenses that are heightened during ovulation:

1) When threatened by sexual assault, ovulating women display a measurable increase in physical strength.

2) Ovulating women overestimate strange males’ probability of being rapists.

3) Ovulating women play it safe by avoiding situations that place them at increased risk of being raped.

4) Women become more racist when they’re ovulating.


Regarding claim #1, PZ Myers points out that the increase in physical strength has not been substantiated. In spite of that, I’ll accept claims 2 and 4 as accurate (I’ll deal with claim #3 in a bit). What claims #2 and #4 do is conflate choosiness with rapist avoidance. If women are evaluating men on a scale from ‘Eek! Creepy rapist’ to ‘I’ll do him right here on the table’, we would expect more selectivity during ovulation (i.e., a bias towards the ‘Eek!’ end of the scale). Rape avoidance postulates that selectivity exists as a specific separate behavior from choosing males in general. I wouldn’t be surprised if, on average, women are more choosy when ovulating: pregnancy imposes significant costs in terms of vulnerability while pregnant and death during pregnancy (in the absence of modern ob/gyn care, birth has a pretty good chance of killing the woman). But that’s not specifically rape avoidance, but part of a larger, more inclusive behavior of mate choice (of course, this supposes that women actively choose men, as opposed to being passive sperm receptacles). Likewise, regarding claim #4 (racism), there is some literature that suggests women, on average, prefer men whose appearance isn’t too different from what they grew up around. Again, if ovulation makes women more choosy, then what is being called ‘racism’ is actually honing in a familiar image. It’s not racism per se; it’s simply setting the bar higher. Women will be less likely to deviate from the ‘normal’ appearance when the stakes are higher.

Claim #3 is really problematic. The article claims:

German investigators Arndt Bröder and Natalia Hohmann established, ovulating women are not less active in general–they’re still busy shopping, going to church, visiting friends, and so on–but they avoid doing those things that make them sexually vulnerable. (link is to a pdf)

I’m not sure they’ve established much of anything. Risky versus non-risky activities were scored by 23 women on a scale of 1-5 (5 being the most risky), and the average score was used. I would have used the median score instead: a few ‘nervous Nellies’ could easily raise a score. This sounds technical, but it could make a huge difference in scoring. I’ll also note that college students were used to assess risk, and college students are fantastic risk assessors (Got Four Loko?) But what really bothers me is this figure:

ovulation 2

The largest change in behavior is among women not on the pill (the pill simulates some of the effects of pregnancy, most notably preventing ovulation): they increase non-risky activities, far more than they decrease risky activities (which is still statistically significant). Ovulating women seem to be more active overall. Maybe ovulation makes women want to do more stuff, and that causes a decrease in risky activity–there are only so many hours in a day. Finally, by the authors’ own admission, this is a relatively weak effect (related to this, keep in mind the scoring caveat noted above). One study that demonstrates a weak effect needs a lot more follow up (didn’t the sciencebloggysphere just have a humongous conniption fit over the Decline Effect?).

As PZ concisely put it:

There are days when I simply cannot bear the entire field of evolutionary psychology: it’s so deeply tainted with bad research and a lack of rigor. And that makes me uncomfortable, because the fundamental premise, that our behaviors are a product of our history, is self-evidently true. It’s just that researchers in this field couple an acceptance of that premise to a deep assumption of adaptive teleology, the very thing that they should be evaluating, and produce some of the most awesomely trivial drivel.

This evidence simply doesn’t meet the standard.

Related posts: Emily Yoffe, Echidne, Jerry Coyne, and Amanda Marcotte (here too) also comment. Also see John Rennie and Amanda Schaffer.

An aside: Why does no one include lesbians in these studies, many of whom have no intention of getting pregnant to have offspring? Seems that would be very elucidating….

Comments

  1. #1 Anisha
    January 20, 2011

    “what is being called ‘racism’ is actually honing in a familiar image. It’s not racism per se; it’s simply setting the bar higher. Women will be less likely to deviate from the ‘normal’ appearance when the stakes are higher”

    i.e. Racism. You apologist.

  2. #2 Tulse
    January 20, 2011

    evol psych is a justification for middle-aged faculty to sleep with their younger graduate students

    …which is clearly an adaptive strategy. See, they can’t help it!

  3. #3 Kemanorel
    January 20, 2011

    i.e. Racism. You apologist.

    Okay, assuming what was said is true, that the “normal” is whoever is closest to what they grew up around. That determines a comfort factor.

    Let’s say a white family lives in a mostly black area, and said white family has a daughter who grows up around mostly black people.

    Let’s say this girl was surveyed for this study and she said the opposite was true… that she was more suspicious of white men than black men while ovulating. Does that make her racist against white people?

    What if you found out it was the opposite for black women, and they’re suspicious of white men? What if they’re suspicious of black men because they grew up in a mostly white area? Does that make them racist against thier own race?

    There’s a difference between being comfortable around what is “normal” and actively dispising something like a racist would.

    Stop trying to see something that isn’t there.

  4. #4 Calli Arcale
    January 20, 2011

    1) When threatened by sexual assault, ovulating women display a measurable increase in physical strength.

    WTF? Seems to me that’s a fight-or-flight response, not rape avoidance. Women don’t want to be raped not merely because of pregnancy concerns but because it would HURT and would be deeply wrong. It would be a terrifying, brutalizing experience.

    Besides which, that “measurable increase in physical strength” can’t be good for a whole hell of a lot given the frequency of rape in many parts of the world. It also conjures up uncomfortable thoughts of the many cultures which, through history, have deemed a sexual assault “rape” only if the woman successfully fights the man off, or causes him significant harm, or receives significant harm herself. If she’s overpowered, it means she actually consented. While I’m sure the researchers didn’t have that in mind, it does have uneasy parallels to the idea that rape is something women generally won’t permit.

  5. #5 Confounding
    January 20, 2011

    I’ll likely post longer thoughts on my own blog later today, but I find myself agreeing with you and PZ on the state of evolutionary psychology at times. Some small statistical effect is found, and as you so well put it, a just-so story, usually involving sex, is invented whole cloth to explain it.

    You can hear the causality framework start to creak almost immediately. My personal favorite was a recent one about why men sleep closer to doors than women – the explanation being it protects our precious baby-making womenfolk from predators entering the cave. For that one, there wasn’t even a statistical justification, just “this is how it works”.

    I then spent ten minutes pondering what it meant that I slept closer to the window in my last apartment.

  6. #6 Hope
    January 20, 2011

    An aside: Why does no one include lesbians in these studies, many of whom have no intention of getting pregnant to have offspring? Seems that would be very elucidating….

    I don’t think women intentionally think to themselves… Hmmmm I sure do want to get pregnant so therefore I am going to act such and such a way. I mean, most women don’t go around behaving based entirely on whether they want a kid. These behaviors aren’t supposed to be rational decisions like – that guy is better because his genes will be really good! It’s more: I want to bed him because he’s pretty! So, I would expect lesbians would not have any clearly different having or not-having a baby intentions in the sack than straight women.

    It would be interesting to see if lesbians have similar long-term/short-term mate choices as straight women. But I don’t think it’s going to tell you anything about behavior based on ovulation.

    Also, I admit, I didn’t read these articles myself, but isn’t this more the fault of the person writing that Slate article and not particularly evolutionary psychologists? I mean, you said they admitted the results were weak in the study. I often find that in a research article that isn’t very convincing the authors may make this pretty clear, but it still ends up in on the internet with crazy, over-credulous headlines.

  7. #7 CherryBomb
    January 20, 2011

    What has bothered me about evolutionary psychology people is that they seem to seriously underestimate the difficulty of what they are trying to do. They usually make the unstated assumption that they can draw a box around some behavior (like risk avoidance) and call it a “trait” that has responded to environmental pressure in some linear way.

    In fact, a person’s behavior in a certain situation is some complicated function of all the traits which actually HAVE evolved due to selection pressure, combined with effects of the environment she grew up in. All the parts of this function are interacting with each other in non-linear ways. How do you tell whether what you are observing is a trait or is just emergent behavior of the system? I think it would be very hard to do, but absolutely necessary before anyone starts spinning rape-avoidance fantasies.

  8. #8 Kirsi
    January 21, 2011

    I was thinking about the ‘racist’ part myself, as in should it be called racism or not. I don’t see myself as a racist (I don’t think people of certain race are inferior or superior, or that race defines our personality or bahaviour), but I have noticed that I don’t have crushes on black men. Years ago I came to the conclusion that it’s because I grew up in a 100% white (caucasian) environment – not a single person of different race in my schools for almost 12 years. Never had a crush on a black actor, even though I find many of them both goodlooking and charming, so they’re not just one “blob” for me either. So my situation is pretty much what Kemanorel describes. Should I be called a racist? I also have a tendency to have crushes based on certain traits inside the “white” male population, so maybe I’m a super racist? (And no, I don’t think african and caucasian are the only races that exist, but the rest would be somewhere in between of those when it comes to romantic/sexual attractiveness, and I’ve had a couple of romantic interests in that group.)

  9. #9 scathew
    January 21, 2011

    In regards to racism, I think we’re all too quick to say, “I’m not a racist.” Personally, I believe we’re all racists. I know when I pay attention (unfortunately) that I am.

    Dabbling in a little unsubstantiated evolutionary psychology here myself, it seems pretty obvious to me that the human brain is a giant categorizing engine (or as WikiPedia puts it – uses “categorical perception”, or “CP”). It wants to say, “Things that look like X are always Y.” That is a huge optimization both in terms of storage and retrieval, but also for food selection and self-protection mechanisms. Being able to say, “Anything that looks like this is good (safe) and this bad (dangerous)” is an extremely useful talent.

    Unfortunately, this engine is also used to apply to people. I suppose at one time that may have been useful, since differences in features may have made it easier to identify your tribe and thus the ones who probably don’t want to kill you for territory etc., however now in a more enlightened world it is a significant burden.

    If you doubt you are wired for “racism”, consider how we choose mates. We all “sort” (categorize) for certain features. We often choose (or show preference) based on extremely surface items like hair color, eye color, shape of this part of the body, or that. So, how is that much different or less arbitrary than making decisions on the color of skin? Is technically deciding, “I’ll sleep with this person because they’re ‘pretty/handsome’ but not this person because their ‘ugly’,” really any more fair than thinking, “They are not my color so I don’t trust them”?

    Or even consider our initial reaction to people at all – don’t we all immediately draw positive or negative inferences of people just by certain facial characteristics? I know that people who features remind me of someone who was say mean in grade school I find myself immediately disinclined to, while others that have faces that remind me of my friends, I’m attracted to. While it might not drive my end behavior, it certainly has some initial influence.

    And the point about “not drive my end behavior” is probably most important. We are wired for all sorts of things like violence, selfishness, perhaps rape (though personally, and thankfully, I’ve never felt the urge), and a thousand other “animal” tendencies that we’ve used our intellect to determine are counterproductive or just plain wrong.

    So what I would argue – it’s not being a racist that is wrong, it’s acting on racism that is wrong. You are what you are and you feel what you feel. What you do have control over, however, is how you act, and that is where I would argue one has a responsibility – to endeavor to minimize our inherent racism’s internal and external components.

    In the end we should stop trying to pretend that we don’t fit in the, ehem, “category” of racist (`cause that would make us “icky”), but instead make sure we don’t act in the category of racist. Admitting it and trying our damnedest to ameliorate it is a lot more constructive than trying to pretend it doesn’t exist.

    As a closing note, I have focused on the physical here to simplify the argument, but there are a lot of other tools our brain uses to categorize other humans, from the sound of the voice, known affiliations, etc., etc. Those too can influence or create prejudices (categorizations).

  10. #10 Kirsi
    January 21, 2011

    Great comment, scathew. I agree with you in that we all have prejudices(sp?), no matter what we call them. What I think makes a ‘racist’, is not being able to see past our prejudice, as you conclude we should. But since we are on the topic of sexual behaviour, it can be a bit hard to change what kind of appearence and behaviour turns you on or raises romantic feelings… I’m not saying it’s impossible, but should we try to mate with all kinds of people (different races, income level, education, looks, ages), just to not act racist?

    I didn’t read the papers either, but what struck me was the amount of test subjects – 23 seems like a very small sample when evaluating something like self observed activity level?

  11. #11 Phoebe Fay
    January 21, 2011

    My fingernails tend to be nice and healthy when I’m ovulating, and then half of them break in the week before my period. I suppose rape-obsessed evolutionary psychologists hellbent on justifying their own freaky biases would conclude that I lose the ability to scratch an attackers eyes out once I’m not ovulating because then getting raped just isn’t as big a deal. Arghh.

    Honestly, I think that saying evol psych is a justification for middle-aged faculty to sleep with their younger graduate students is giving some of these guys too much credit.

  12. #12 Dani Long Noriega
    January 24, 2011

    Racism is too simple a term for it. I’m a 42 year old middle class white female, but adolescent white-trash males walking down the street behind me or towards me would intimidate me more than young African-American males who carried themselves with respect – regardless of my ovulation cycle.

    It’s more about familiarity and predictability than race itself. We (humans) like to feel safe, and we feel safe when we believe people around us are going to behave similarly to us and predictably and we can understand their thinking and rational for their behavior. If we think we have things in common with them, we’re going to feel safer – that will have to do with dress, how they carry themselves, how they talk, how loud they are, etc. more than skin color or the shape of their nose or the color and texture of their hair (although these can be easy things to target first).

    I never understand why these types of studies muck this up so much and make it so over-complicated.

  13. #13 Raven
    January 26, 2011

    “(in the absence of modern ob/gyn care, birth has a pretty good chance of killing the woman)”

    Buh?

    Then how have we all gotten here? Did women have twins a lot back in the day, managing to reproduce themselves effectively before dying off? Doesn’t birth, logically, need to be a pretty safe process?

    There are studies to quote comparing the U.S. to other countries that use far less ob/gyn care and achieve much better mortality/morbidity outcomes than the U.S. has, but I mean, just think about it.

  14. #14 Brad K.
    January 27, 2011

    I could turn the list of reactions at ovulation around. I could posit that women, when ovulating, are more intently focused on a safe and secure home, and closeness (and arousal for) a trusted mate.

    The result would be more mating/bonding, and more sexual activity when more fertile. That seems activity quite likely to survive natural selection.

  15. #15 Wow
    January 28, 2011

    “Then how have we all gotten here?”

    Because fertility rates are high.

    If 50% of women die in their first childbirth and 50% die in the second, etc, then we still have 2 children per woman average which is enough to continue the species, near enough.

    It’s not that high to begin with, and if it were, the later births are lower because the body has ironed out some of the problems by then. Mortality in childbirth rises again later when either age or the strain of continuous childbirth weakens the mother.

    Now, if you were required to play russian roulette once every year, that would be a 15% chance of death, much less than the 50% I cited above and therefore much less unsafe, would this be considered dangerous or not?

    How about if you had to play it after every child you weaned?

    Death rates of 1% mean that maybe 30 million women die in childbirth each year.

    I’d call that dangerous.

  16. #16 SocraticGadfly
    January 29, 2011

    Mike, I’ll go further than you.

    First, I love philosopher of science David Buller’s distinguishing between legitimate ev psych (what little there is, any more) and what he first called Pop Ev Psych.

    Second, Pop Ev Psych, IMO, is actually nothing less than Social Darwinism in new dress.

  17. #17 pik
    March 6, 2011

    I’m a little late to the party, but had to comment on -
    “Why does no one include lesbians in these studies, many of whom have no intention of getting pregnant to have offspring?”

    Wouldn’t it be far more appropriate to compare women who want children to those who do not? The desire to have children is not at all the same thing as one’s sexual orientation. I admit ignorance on studies about this, but my personal experience shows no link whatsoever between the two.

  18. #18 Antonia
    March 27, 2011

    @ pik: You are making the assumption that lesbians are lesbians because they don’t want children. I don’t have the statistical data on the subject, but having grown up in the San Francisco Bay Area and now living in Palm Springs, I can assure you that many lesbians go to great lengths to be artificially inseminated or end up adopting children. Lesbians are lesbians because they aren’t attracted to men and they are attracted to women.

    That being said, I simply don’t understand why it would matter whether a woman wants children or not in regards to being raped. Maybe I am just missing something from the article and/or the study, but I was molested as a child and raped as an adult and I am unsure of whether or not I want children. My desire or lack-thereof to have children doesn’t seem to have mattered at all in either case. Is it a matter of pheromones making a woman more attractive to men and therefore more likely to be raped? Maybe someone can clear up my confusion for me.