Wednesday, February 1, 2012

The Science Of Being A Bitch To Sluts

A while back, some of you may remember that an event called "SlutWalk" took place. For those in need of some background, a Canadian police officer suggested that women should avoid dressing like sluts to minimize their chances of being raped. In protest against these remarks and to fight back against "slut-shaming", marches of predominately young women took to the streets to announce that blaming the victim in rape cases because of how they were dressed was wrong. One would think, given the turn out of predominately young women, that these young women also believe that it should not be acceptable to be aggressive towards others or mistreat them because of how they dress or how "slutty" they behave sexually, no matter the context. One would be wrong.

There are some research papers that are such a breath of fresh air it's like falling in love with science all over again; this was one of those papers.

                                                                   The feeling is similar to this, but without all the allergies and ticks.

The paper, by Vaillancourt and Sharma (2011), was examining intrasexual competition between women, specially the proposition that women would be relatively intolerant of other women they perceive as being sexually promiscuous. There are three delicious ironies to this paper, as it relates to Slutwalk: first, the authors are both working in Canadian universities. Second, the subjects being studied were all young women. Lastly, all the experimenters manipulated was the clothing that a female confederate was wearing; she was either dressed conservatively or, well, slutty (actual pictures of the clothing the confederate wore can be found in the study itself). To celebrate the return of Tosh.0 for its forth season, let's play a round of "guess what happens next".

Here's the setup: two women between 17 and 23 years of age are in the lab, sitting opposite each other for what they think is an unrelated experiment. The two women are either friends with each other or strangers. There's a knock on the door. It's the confederate, who happens to be an attractive young woman (independently rated as an 8.6 out of 10). She walks between the two subjects and asks them about the experimenter's whereabouts; the confederate then leaves with the experimenter. In the first condition, she walks in dressed conservatively. Can you guess what happens next?

If you guessed that there's next to no negative reaction, you'd be right on track. In the second condition, the confederate is dressed in a black mini-skirt and a low-cut top. Can you guess what happens next in this case? If you guessed that reaction of the two female subject's behavior would be classified as "bitchy" (including such behaviors as glares, looking the confederate up and down, saying something negative after she left the room, or laughing at her) by independent raters roughly 75% of the time, you probably weren't marching in any SlutWalks. If you further guessed that of the subjects who displayed true happiness at the confederate (11.6%), all were in the conservatively dressed group, and all the women who displayed anger at the confederate (12.6%) were in the sexy condition, I'll award you one genuine fake PhD in psychology.

                                 When you consider that most people waste years trying to get a similarly useless piece of paper, you'll realize you got the better deal.

While friend dyads were rated as slightly bitchier than strangers, the effect was small so there might not be too much to make of it. A second experiment was run. This time, there were three pictures of the same confederate as before: in one picture, she was dressed conservatively, in another she was dressed sexy, and in a third, she was dressed sexy, but the picture was manipulated to make her look overweight. A new sample of young women, ages 17 to 28, who were rating the pictures said they would be much less likely to introduce the confederate to their boyfriends, let their boyfriends spend time with her alone, or befriend her themselves when she was dressed proactively, and that effect remained even in the photos manipulated to make her look fatter.

It would seem the picture we're getting is that women don't seem to trust, much less like, other women that they perceive as being promiscuous. Cues for promiscuity appear to be threatening and unappealing. Why might this be the case? One part of that answer is male investment. The more freely available sex is, the less willing men will be to invest in obtaining it; simple supply and demand. Each additional promiscuous woman lowers the collective value of sex, in turn lowering the amount of investment a woman can demand. This suggest that women, regardless of whether they're sexually promiscuous themselves, would tend to be at least somewhat put-off by other women's sexual availability and actively work to restrict it through aggression. Indirect kinds of aggression, such as insulting and social exclusion, are the most common.

                                  However, it's not a protest designed to stop other women from judging you, making fun of you, or excluding you for being a slut.

It would seem this effect is not limited to just sexual promiscuity, however, as attractive women are less likely to be hired, but only when it's another woman doing the hiring. For a woman, having other attractive and/or promiscuous women hanging around does you no favors when it comes to obtaining sustained male investment. Accordingly, those types of women who pose a threat do not seem to meet with warm welcomes. 

In my previous post, I mentioned an idea it's now time to return to:
Both articles above seem to equate sexualization with sexism, though precisely why that link is supposed to exist is left unexplained. It's almost as if their implicit proposition is that either (a) women can be sexually attractive, dressing and/or acting provocatively, or (b) be valuable and respected, but not both.
Female comic book characters are often depicted as being sexually attractive and dressed in a provocative manner, which is the aforementioned volatile combination that leads to female disdain. It might be hard for many women to identify with those characters or accept them because they're too busy hating them for what they represent. Now, I already hear someone saying, "But those two articles complaining about how it's wrong to sexualize fictional female characters were written by men, and this research paper talks about women's reactions. How can there be any connection?" There are two possible ways to make this connection that immediately come to mind.

The first is that not all men are equally desirable. If pair-bonding goes the way of the dinosaurs, the men at the lower ends of desirability spectrum lose out the most, while those at the top gain the most. Why? Just because a woman is promiscuous doesn't mean she's indiscriminant. If she's not getting the investment, she may as well go all-in for the good genes, effectively shutting most men out. This is the case in the majority of species without male investment. Because of this, men on the lighter end of the desirability scale have more of an incentive to attempt and encourage pair-bonding styles of mating. Since promiscuous women are a threat to maintaining pair-bonds, and generally out of the reach of those men anyway, the women are imposing costs with no associated gains and are looked down upon.

The second, perhaps more cynical, and by no means mutually exclusive, explanation is that some of the reason men look down on sluttier women is that they are trying to get in good with the more conservative women who are already looking down on the sluttier one. More succinctly, some men join in the derogation in the hopes of getting laid. To what extent that's their proximate motivation is an open-ended question.

References: Vaillancourt, T. & Sharma. A. (2011). Intolerance of sexy peers: Intrasexual competition among women. Aggressive Behavior, 37, 569-577. 


  1. Great post. This subject is near and dear to me as it combines two of my favorite subjects, game theory and evolution. From what I understand, punishing non-cooperators can lead to a stable strategy, as well as punishing those who fail to punish the non-cooperators. Specifically, the ESS which would lead to male investment to 'right' natural imbalances in reproductive resource investment between the sexes.

    As for the pair bonding discussion. It's interesting to see it from the male perspective as less to do with punishing the non-punishers and more in light of a fact gleaned from another of your posts: that we have twice as many female ancestors than male ancestors. It is beneficial for a certain population of males (perhaps in this case the majority) to support a monogamous minimax strategy to hedge against their (in)ability to compete.

    I would be interested if you have written more on pair bonding in the human primate, and perhaps in particular on the history and recent declining adoption/success rates of marriage. It seems in more egalitarian, secular or wealthy communities, marriage and population rates decline.

    1. I can't prove it, but I'm fairly sure that in recent times, pair-bonding has actually increased, but only amongst certain types of people.

      Now, I'm a big believer in the existence of rapid evolutionary shifts amongst large populations (see The 10,000 Year Explosion by Cochrane and Harpending). Essentially, new ecological niches are more rapidly filled in species that have very rapid reproductive rates. Most people, when they think of rapid reproductive rates, think of species like fruit flies that have quick reproductive cycles.

      However humans also fill this category because, despite our slow reproductive cycle, there's just so damn many of us that new mutations are appearing all the time. And while mutation rate is linearly dependent on population size, beneficial mutations spread exponentially through the population (2 offspring, then 4, then 8, etc). The result is that humans can rapidly evolve to take advantage of new survival circumstances.

      So what circumstances might those be? One of the biggest changes that has appeared in the last 10,000 years is the appearance of economic specialization. In a hunter-gatherer society, there are two professions: hunting and gathering. Neither of them are *that* cognitively demanding, the don't require us to learn particularly difficult mental models, at least when compared to computer programming or engineering or science.

      The one thing that survival in a small, violent hunter-gatherer society does require is complicated mental models of the local political hierarchy. It doesn't hurt of course that we can apply those mind-reading models to other complex systems ("the god of rain is unhappy" or "these deer are scared") but their primary purpose is to avoid getting killed in a political coup, getting left out of a hunting party, or suffering from mate poaching.

      But, sociality being a largely zero-sum game, these mental models are extremely cognitively taxing. However, what if you lived in a society that didn't require them? What if you lived in a society with a police force, and taxes, instead of politics and violence? What if you needed all that brain power for something hard, like being a scientist?

    2. Clearly, for a modern, knowledge-worker nerd, wasting valuable brain-space on social skills is kind of a waste. And thus, for the last 10,000 years, humans have had a strong evolutionary pressure to lose social skills and gain abstract thinking skills (assuming that there's only so much room to store mental models in the brain, see the memory-prediction model of cognition or On Intelligence by Jeff Hawkins). There is actually evidence that this has occurred: I uncovered a few articles hinting at a complete absence of autism both in Canadian Inuit populations (, and I emailed the researcher, who confirmed that it's unpublished but valid), and also in Australian aborigines and Brazilian natives. If you're really interested I can provide more details, although like I said, these guys are still working on getting papers out there.

      Okay, so, still with me? Where does this lead us next? Well, if men are losing their social skills and gaining abstact thinking skills (also see Baron-Cohen's extreme male brain and assortative mating theories of autism), wouldn't it be nice if they had a way to compensate, strategically, for these deficiencies? Indeed.

      Pick-up artists notwithstanding, the usual way for nerds to compensate is by following a strongly pair-bonded strategy, whereby they trade resources for relationship stability, and also offload some of that social-thinking requirement to more socially skilled women. In turn, the women in these highly-pair-bonded, nerd-loving relationships tend to be more dominant as they have a bigger share in the cognitive resources of the pair. Although they tend to also have deficiencies in social cognition, and are usually bullied by more socially skilled females.

      Indeed, I would attribute at least some of the rise of feminism to the rise of these types of relationships amongst intellectuals. Women get used to having the power in a relationships and they start to question whether maybe equality is actually, you know, a human right and stuff... I can assure you though, many more socially skilled women, while they buy into the ideology of feminism, respond sexually only to dominant males who aren't so interested in "partnership". It kills me, because I like to have a partner, but I've learned to live with it when I see it. There's not many young female subs out there, especially not non-nerdy ones. But I digress.

      The point is that intelligence over social skills with pair-bonding is just one life-strategy among many in modern human populations. Some men still like to sleep around (see Richard Feynman). Other men combine social skills with pair-bonding. I know a guy whose Dad has been happily married for decades, and yet the son has slept with well over a hundred of women (he's in his mid-20s) with no sign of a girlfriend. Still pair-bonding is still overwhelmingly the more common strategy amongst classic nerds. No surprise that both Bill Gates and Mark Zuckerberg are happily married despite ample opportunity to stray (unlike many powerful politicians, although Australia's nerdy ex-pm Kevin Rudd remains happily married and socially ostracised within his own party).

      Oh and finally, I think that a lot of the resistance to studying game, pick-up artistry and the mating habits of highly promiscuous men really has more to do with the non-socially skilled pair-bonding nature of the average evolutionary psychologist. No offence. I know, you probably disagree. Everyone (else) is a hypocrite. Social skills are still a hard thing for me to define, but I know them when I see them, and I don't often see them in the evo psych establishment (I'm not so hot myself).

      Okay, sorry about the long comments, I'll stop now!