Is there really a single ideal body shape for women?

Boticelli's "Birth of Venus" c. 1486.
Boticelli’s “Birth of Venus” c. 1486.

Many scholars of Renaissance art tell us that Botticelli’s Birth of Venus captures the tension between the celestial perfection of divine beauty and its flawed earthly manifestation. As classical ideas blossomed anew in 15th-century Florence, Botticelli could not have missed the popular Neoplatonic notion that contemplating earthly beauty teaches us about the divine.

Evolutionary biologists aren’t all that Neoplatonic. Like most scientists, we’ve long stopped contemplating the celestial, having – to appropriate Laplace’s immortal words to Napoleon – “no need of that hypothesis”. It is the messy imperfection of the real world that interests us on its own terms.

My own speciality concerns the messy conflicts that inhere to love, sex and beauty. Attempts to cultivate a simple understanding of beauty – one that can fill a 200-word magazine ad promoting age-reversing snake oil, for example – tend to consistently come up short.

Waist to hip

Nowhere does the barren distinction between biology and culture grow more physically obvious than in the discussion of women’s body shapes and attractiveness. The biological study of body shape has, for two decades, been preoccupied with the ratio of waist to hip circumference.

With clever experimental manipulations of line drawings, Devendra Singh famously demonstrated that images of women with waists 70% as big as their hips tend to be most attractive. This 0.7:1 waist-to-hip ratio (WHR), it turns out, also reflects a distribution of abdominal fat associated with good health and fertility.

Singh also showed that Miss America pageant winners and Playboy playmates tended to have a WHR of 0.7 despite changes in the general slenderness of these two samples of women thought to embody American beauty ideals.

Singh’s experiments were repeated in a variety of countries and societies that differ in both average body shape and apparent ideals. The results weren’t unanimous, but a waist-to-hip ratio of 0.7 came up as most attractive more often than not. The idea of an optimal ratio is so appealing in its simplicity that it became a staple factoid for magazines such as Cosmo.

There’s plenty to argue about with waist-hip ratio research. Some researchers have found that other indices, like Body Mass Index (BMI) explain body attractiveness more effectively.

But others reject the reductionism of measures like WHR and BMI altogether. This rejection reaches its extremes in the notion that ideas of body attractiveness are entirely culturally constructed and arbitrary. Or, more sinisterly, designed by our capitalist overlords in the diet industry to be inherently unattainable.

The evidence? The observation that women’s bodies differ, on average, between places or times. That’s the idea animating the following video, long on production values, short on scholarship and truly astronomic on the number of hits (21 million-plus at the time of writing):

This rather questionable video, called ‘Women’s Ideal Body Types Throughout History’, is getting a lot of airplay on YouTube.

I note that Botticelli’s Venus looks more at home in the 20th Century than among the more full-figured Renaissance “ideals”. So do the Goddesses and Graces in La Primavera. Perhaps there was room for more than one kind of attractive body in the Florentine Renaissance? Or is the relationship between attractiveness and body shape less changeable and more variegated than videos like the one above would have us believe?

Not that I’m down on body shape diversity. Despite the fact that there seems to be only one way to make a supermodel, real women differ dramatically and quite different body types can be equally attractive. The science of attractiveness must grapple with variation, both within societies and among cultures.

Enter the BodyLab

For some years our research group has wrestled with exactly these issues, and with the fact that bodies vary in so many more dimensions than just their waists and their hips. To that end, we established the BodyLab project, a “digital ecosystem” in which people from all over the internet rate the attractiveness of curious-looking bodies like the male example below.

Example image from the BodyLab ‘digital ecosystem’. The VW Beetle is provided as the universal symbol of something-slightly-shorter-than-an-adult-human. Faces pixellated to preserve any grey people’s anonymity. Rob Brooks/BodyLab.biz
Example image from the BodyLab ‘digital ecosystem’. The VW Beetle is provided as the universal symbol of something-slightly-shorter-than-an-adult-human. Faces pixellated to preserve any grey people’s anonymity.
Rob Brooks/BodyLab.biz

We call it a “digital ecosystem” not to maximise pretentiousness, but because this experiment involved multiple generations of selection and evolution. We started with measurements of 20 American women, a sample representing a wide variety of body shapes.

We then “mutated” those measures, adding or subtracting small amounts of random variation to each of 24 traits. Taking these newly mutated measures we built digital bodies, giving them an attractive middle-grey skin tone in an attempt to keep variation in skin colour, texture etc out of the already complex story.

If you want to help out with our second study, on male bodies, visit BodyLab and click through to Body Shape Study and then Rate Males (Generation 6).

This all involved considerable technologic innovation, resulting in an experiment unlike any other. We had a population of bodies (120 per generation) that we could select after a few thousand people had rated them for attractiveness. We then “bred” from the most attractive half of all models and released the new generation into the digital ecosystem.

What did we find? In a paper just published at Evolution & Human Behavior, the most dramatic result was that the average model became more slender with each generation. Almost every measure of girth decreased dramatically, whereas legs and arms evolved to be longer.

In eight generations, the average body became more slender. Waist, seat, collar, bust, underbust, forearm, bicep, calf and thigh girth all decreased by more than one standard deviation. At the same time, leg length (inseam) rose by 1.4 standard deviations. Rob Brooks
In eight generations, the average body became more slender. Waist, seat, collar, bust, underbust, forearm, bicep, calf and thigh girth all decreased by more than one standard deviation. At the same time, leg length (inseam) rose by 1.4 standard deviations.
Rob Brooks

That may not seem surprising, particularly because the families “bred” from the most overweight individuals at the start of the experiment were eliminated in the first few generations.

But, after that, more families remained in the digital ecosystem, surviving generation after generation of selection, than we would have expected if there was a single most attractive body type. The Darwinian process we imposed on our bodies had started acting on the mutations we added during the breeding process.

More meaningful than the mean

Those “mutations” that we introduced allowed bodies to evolve free from all the developmental constraints that apply to real-world bodies. For example, leg lengths could evolve independently of arm lengths. Waists could get smaller even as thighs got bigger.

When we examined those five families that lasted longest as our digital ecosystem evolved, we observed a couple of interesting nuances.

First, selection targeted waist size itself, rather than waist-hip ratio. No statistical model involving hip size (either on its own or in waist-hip ratio) could come close to explaining attractiveness as well as waist size alone. Our subjects liked the look of slender models with especially slender waists. There was nothing magical about a 0.7 waist-to-hip ratio.

Second, within attractive families, which were the more slender families to begin with, evolution bucked the population-wide trend. These bodies began evolving to be more shapely, with bigger busts and more substantial curves.

It turns out there’s more than one way to make an attractive body, and those different body types evolve to be well-integrated. That’s a liberating message for most of us: evolutionary biology has more to offer our understanding of diversity than the idea that only one “most attractive” body (or face, or personality) always wins out.

What about the cultural constructionists? Are body ideals arbitrary, or tools of the patriarchal-commercial complex?

Our results suggest that the similarities between places, and even between male and female raters, are pretty strong: the 60,000 or so people who viewed and rated our images held broadly similar ideas of what was hot and what was not. But their tastes weren’t uniform. We think most individuals could see beauty in variety, if not in the full scope of diversity on offer.

What’s cool about our evolving bodies, however, is that we can run the experiment again and again. We can do so with different groups of subjects, or even using the same subjects before and after they’ve experienced some kind of intervention (perhaps body-image consciousness-raising?). I’m hoping we can use them to look, in unprecedented depth, at the intricate ways in which experience, culture and biology interact.

The Conversation

This article was originally published on The Conversation.
Read the original article.

Are you a feminist? Two simple ways to tell.

Are you a feminist?

It’s a question I ask of my third-year Animal Behaviour class every year. I ask the question in a lecture, near the end of the course, about human sexuality. It’s a part of the lecture where I discuss sexual conflict: the idea that what’s best for one mate isn’t necessarily best for the other.

This leads on to discussion about how sources of power (such as the work women and men can do in a society), and customs that shape the supply and demand of sex can dramatically change human mating patterns. It’s one of those areas where evolutionary biology offers remarkable, powerful insights into difficult political and ideological issues.

I’m always surprised at how few students answer in the affirmative. Last week, when I asked the question, just two students raised their hands. And rather sheepishly, at that.

Many probably equivocated and held back, reluctant to take a position in front of their classmates. Others have probably not really thought about it that much. And others, sympathetic to ideas of equity have been turned off the idea by negative stereotypes of feminism.

Whether or not to identify with feminism, or as a feminist, has never, it seems, been quite as complicated as it is today. Why wouldn’t it be? Hear the words of one of 2013’s most influential women, Beyoncé, this very week playing to packed Australian arenas.

I truly believe that women should be financially independent from their men. And let’s face it, money gives men the power to run the show. It gives men the power to define value. They define what’s sexy. And men define what’s feminine. It’s ridiculous.

The ridiculously confusing bit (something we used to call irony before the hipsters thought it was cool), as Hadley Freeman pointed out in The Guardian earlier this year, is that Beyoncé shares this wisdom in American GQ:

A men’s magazine in which she poses nearly naked in seven photos, including one on the cover in which she is wearing a pair of tiny knickers and a man’s shirt so cropped that her breasts are visible.

Ruminating this weekend over why so few of my smart, engaged students would self-identify as feminists, I was delighted to see this flow-chart in an article by Rebecca Searles, an editor at Huffington Post.

Uncomplicating feminism

Rebecca’s flow-chart is, of course, a massive oversimplification. With a delectable bit of polemicism thrown in: if you aren’t in favour of equal rights and opportunities then “you probably suck as a person”. It probably won’t become the new litmus-test for a suddenly unified global feminism. But she makes a valuable point that, in a world where rights and opportunities are far from equal, those in favour of equality, or equity, should seek to find and identify with one another.

Searles designed the flow-chart in exasperation at contemporary pop-stars and teen role models who misuse the term “feminist”, thus both undermining feminism and sounding “like idiots”.

If you’ve read this column, or my book, you’ll have a fair idea of my politics. Many of my favourite commentators on this site call me a feminist, thinking it’s a perjorative term. Which makes them sound, as Rebecca Searles might say, “like idiots”. But forced to label myself, I’d call myself pro-feminist.

Why so reluctant to call myself a feminist? As a man, I’ve always felt it safest to stay outside the tent, happy for the title to be conferred from within but reluctant to claim it for myself.

It’s a position reinforced earlier this year with the spectacular fall from grace of Hugo Schwyzer, the internet’s erstwhile highest profile male feminist. Schwyzer rather dramatically quit the internet (how is that even possible?), twice, when his troubled personal history and a recent affair caused a rather spectacular swing against him in his own constituency [I’ve collated some of the key links here].

There is inherent peril, I feel, for a man who leans too heavily on his feminist credentials. Some, like Schwyzer, have Tyrannosaur-like skeletons in their closets. All of us have the inevitable flaws to which human flesh is heir.

I’m not the only one for whom the word “feminist” conjures an exclusively feminine image. Consider the hilarious Caitlin Moran. In her recent book How to be a Woman, Moran first laments the same confusion among women over whether to identify as feminists:

We need to reclaim the word ‘feminism’. We need the word ‘feminism’ back real bad. When statistics come in saying that only 29% of American women would describe themselves as feminist – and only 42% of British women – I used to think, What do you think feminism IS, ladies? What part of ‘liberation for women’ is not for you? Is it freedom to vote? The right not to be owned by the man you marry? The campaign for equal pay? ‘Vogue’ by Madonna? Jeans? Did all that good shit GET ON YOUR NERVES? Or were you just DRUNK AT THE TIME OF THE SURVEY?

Moran then offers what, after Searles’ flow-chart, must be the second most pithy test for the question “Am I a feminist?”

So here is the quick way of working out if you’re a feminist. Put your hand in your pants.

a) Do you have a vagina? and b) Do you want to be in charge of it?

If you said ‘yes’ to both, then congratulations! You’re a feminist.

Moran’s book is, of course, about How to be a Woman – it says so in the title. She writes for the Beyoncés and the Katy Perrys, and more particularly for the women who revere them and think that Keeping up with the Kardashians might be a pretty neat idea. She’s not offering serious “am I a feminist?” advice to academic men who understand that equitable societies are the best kind to live in.

But Moran’s rather anatomic test reinforces my concerns about whether a man can ever claim to be a feminist in the same rock-solid way a woman can. Even though I’m entirely clear on the importance of feminism and of equity.

But it does seem clear to me that the question “am I a feminist?” should be a simple one for any woman to answer, irrespective of whether they use Searles’ method or Moran’s.

Rob Brooks does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

The Conversation

This article was originally published at The Conversation.
Read the original article.

Shutting that whole thing down: Todd Akin, rape, pregnancy and abortion

Like almost everybody else I spoke to today, I was staggered, this morning, to hear Todd Akin’s comments about “legitimate rape” and pregnancy. The Missouri Republican, who is running for Senate, was justifying his opposition to abortion even in cases of rape, when he offered up the following cringeworthy utterance:

From what I understand from doctors, [pregancy resulting from rape is] really rare. If it’s a legitimate rape, the female body has ways to try to shut that whole thing down.

It’s possibly the biggest news story in the world right now, but if you missed it, Nicole Hemmer has done a wonderful job here at The Conversation dissecting the responses to Akin’s comments and their likely campaign-aborting implications.

As Hemmer and others point out, Akin’s comments are very much an extension of the so-called “Republican War on Women”. The Republican party finds itself unfortunately captive to evangelical zealots whose bronze-age cosmology is matched only by an antediluvian attitude to sexuality, sex and reproduction. It should surprise nobody that women (like atheists and homosexuals) are far less likely to vote Republican than men are. What surprises me is how many women do vote Republican.

I couldn’t do justice to just how ignorant Akin must be to even consider qualifying “actual rape” from any other. Fortunately columnists, bloggers and tweeters everywhere have been hard at it since Sunday morning. But what struck me most was his pseudo-medical contention that “the female body has ways to try shut that whole thing down.”

That is an assertion that strays right into my research specialty: the biology of sexual conflict. I’ve written many times before about the fact that the reproductive interests of a man and a woman are seldom perfectly aligned and can be quite profoundly out of whack. A wife and husband who differ on whether to have another child are in mild sexual conflict, whereas a rapist and his victim are – it would be hard to overstate this – at profound odds (evolutionarily and otherwise).

Women and men, like all sexually reproducing animals, negotiate the decision over whether to mate or not. The outcome isn’t always a happy compromise because sometimes the mating is worth much more to one party than the other. But in some species, a female can choose – after copulating – not to use the sperm of a male.

In the Australian Black Field Crickets we use in my lab, the male cannot copulate forcibly with the female. She has to mount him voluntarily and she is unlikely to do so unless he has a sexy song. But once she has mated him and he has attached a bag of his sperm (a spermatophore) to her abdomen, she often chooses to remove it before its entire contents enter her body. This isn’t in the male’s interests and he harasses her to prevent her reaching around and removing the spermatophore.

Perhaps this is the kind of thing Todd Akin had in mind? Post-rape female choice in humans in which women have some kind of adaptation that prevents conception with the sperm of a rapist. I always savour the irony when an evangelical evolves into an armchair adaptationist.

If such an adaptation existed, it certainly doesn’t work particularly well. According to one U.S. study, “national rape-related pregnancy rate is 5.0% per rape among victims of reproductive age”.

My point here is not to get sidetracked in the largely irrelevant biology of whether women can, somehow, discriminate against the sperm of a rapist. I would rather highlight the fact that the way in which women discriminate against men whose children they do not want to carry is by not having sex with them in the first place. A measure of the extent to which a society deserves to consider itself civilized can be gained from the extent to which its citizens recognize this fundamental and inviolable right.

When this right is violated or subverted, be it via incest, or violent coercion, or any other means whatsoever, the result is rape. To suggest that some forms of rape earn that name more legitimately than others is to deny women this right and to defend the agenda of the rapist.

But in societies like ours, there are other very effective mechanisms by which women can choose not to bear a child by a particular man, including a rapist: abortifacient drugs and abortion. Bill Clinton famously asserted that “Abortion should not only be safe and legal, it should be rare”. Even the most ardent pro-choice advocates agree that abortion should be rare, but without legal and safe abortion women fare considerably worse in the messy business of sexual conflict and in society as a whole.

What strikes me about the anachronistic attitudes of evangelicals and their Republican puppets to abortion, contraception, family planning, female economic empowerment and feminism in general is just how unambiguously male these attitudes are. All of these issues are informed by what suits men’s evolutionary and economic interests. Or more precisely by what suited the interests of men, especially rich and powerful men, before the industrial revolution.

An entire political party in one of the most advanced and educated countries on earth has become a caricature of the most basal evolved insecurities about masculinity. They seem terrified of losing control over the means of reproduction and petrified of cuckoldry.

————————————————————————-

Rob Brooks does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

The Conversation

This article was originally published at The Conversation.
Read the original article.