Cordelia Fine has a great short piece, Will Working Mothers’ Brains Explode? The Popular New Genre of Neurosexism, on the recent spate of work about the ‘female brain.’ In the article (which is short but worth reading, including for the other material she links to), she explores ‘several recent popular and influential books arguing for fundamental and “hard-wired” differences in male and female psychology.’ In her discussion, she doesn’t so much focus on the research itself but on the question, ‘What accounts for the success and appeal of the new field of neurosexism?’ I’m going to take this posting as a license to range all over the place on the ‘biology’ of sex differences, not just in the brain, as a way of thinking more about how culture and biology become inextricably entangled even in basic sexual differences, like say body size.

One explanation for neurosexim, according to Fine, is that ‘Most lay readers, of course, have neither the background nor the resources to question the many inaccurate and misleading claims made about gender differences in the brain,’ a discussion that we’ve already had on Neuroanthropology (both here and here). I especially like a quote that Fine borrows from Mark Liberman: ‘misleading appeals to the authority of “brain research” have become the modern equivalent of out-of-context scriptural fragments’ (originally on Language Log).

Fine presents the example: ‘The back cover of The Female Brain offers to explain why “a man can’t seem to spot an emotion unless someone cries or threatens bodily harm”. Were we to pick up a different sort of book that made an equally unusual sort of claim (a guide to pets, say, which promised to explain why cats can’t climb trees), we would immediately put it down and go in search of a more reliable text.’ It’s a great point; so much of our experience points to myriad exceptions to these neurosexist rules, and yet many of us don’t throw the books out immediately. Odd…

Fine’s other explanations for our susceptibility to neurosexism are more along the lines of motivational theories: men put up with having their empathetic capacities roundly dismissed because it is ‘a small price to pay for licence to lay claim to more valued and potentially profitable psychological advantages.’ In contrast, women endure or even embrace neurosexism because of a ‘palliative system justification motive’: research has found that ‘lower status groups have a remarkable capacity to rationalize what goes against their self-interests, internalize limiting stereotypes, and find legitimacy in the very inequalities that hold them back.’ Alright, not too much interesting here — we invest in gender stereotypes either because we gain from them or because they make us feel better about being shafted.

More interesting is the effect of social roles on gender stereotypes: ‘Davis’ recent longitudinal study of gender ideology found that young adults shed their gender egalitarian beliefs once they had children, but only so long as their procreation was normatively timed, indicating that it is not the experience of having children per se that causes gender ideology to change. Rather, there may be something special about taking on a culturally loaded adult role’ (Fine’s reference to Davis 2007). If I had a dime for everytime someone said, ‘I used to believe boys and girls were the same until I had my son/daughter,’ I had… well, several more dimes. That is, I do think that having children — those short, powerful living anecdotes — does affect the way that many of us think about sex differences.

One other explanation I think might be worth considering is that bad ‘neuroscience’ (like patriotism) is the last refuge of scoundrels. That is, many other rationales for sexism have been severely undermined; we have ample evidence that women are capable of doing every conceivable job (except maybe sperm donor), girls score as well as (or better than) boys on tests of intellectual potential, and ideologies that have long justified structural sexism — such as some religions — are under attack from all quarters. In this context, it’s not so much that sexism is a strong, expanding ideology, but rather that it is increasingly retreating, searching for some sort of justification, both for its existence and for its normativity. That is, if all structural constraints on women have been removed (I don’t believe this), then why are women still not equal? Or, if we can’t justify sexism by reference to the Garden of Eden, then how do we justify it? It must be in our brains…

But Fine also goes on to point out that research in social psychology, stereotype priming, and other gender-linked phenomena shows that the promotion of these stereotypes has real behavioural effects. To summarize:

there is evidence that accounts of gender that emphasise biological factors leave us more inclined to agree with gender stereotypes, to self-stereotype ourselves, and for our performance to fall in line with those stereotypes…. Moreover, other research from the social psychological literature has shown that presenting cognitive or emotional tasks in ways that make them seem diagnostic of gender tends to set up a self-fulfilling prophecy …. [see Fine’s original piece for a host of supporting references]

Distinctions between the sexes seem to me to be one of the places where the naturalization and essentialization of differences produced by developmental unfolding, culture-biology tangles, is greatest. That is, even more than ‘race,’ people are liable to attribute differences that they perceive between men and women to an essential distinction deep in the soul/hormones/brains/viscera or wherever they locate that difference. Sexual dimorphism in humans is both physiological and cultural; I always have to laugh when someone points to the difference between strength in men and women as ‘natural’ and inevitable, for example. I work with athletes, so I’m well aware that women power-lifters, Brazilian jujitsu practitioners, arm-wrestlers, or competitive wood-choppers (just to cite a few examples) are far stronger or more physically capable than average men in the same activities.

Like me, Fine has a problem with the use of computer hardware metaphors for the brain: ‘with the buzz-phrase ‘hard-wiring’ comes an extraordinary insistence on locating social pressures in the brain.’ While some dimorphic traits seem to be tightly constrained by physiological heredity, so many of the ones that we point to and are most interested in — personality, aggression, strength, intellectual ability, emotional perception — are precisely in those traits that we know are most developmentally plastic and subject to training effects. That is, we know damn well in our own lives that our math ability is affected enormously by our training and practice, and yet we overlook this fact when we hear claims about the difference between girls and boys mathematical ‘potential.’ In the case of the brain, we know that even the connections between the eyes and the visual cortex are not ‘hard-wired’ but must emerge through sensory stimulation and developmental processes; how much more likely is it that our ability to empathize with each other is susceptible to all sorts of developmental pressures?

In other words, I’d have more sympathy for the gender essentialists if they weren’t choosing such lousy traits to argue with, pointing to abilities that we KNOW in our own lives are subject to modification. I was a ‘math-lete’ before I went to college, but I really didn’t want to follow my father into accountancy, so I know my abilities have atrophied (at least, those that I don’t use frequently). It’s so patently obvious, for example, that people around me are more or less empathetic depending upon their own experience; why do the neurosexists point to these sorts of traits when they want to make their arguments? It’s like the argument about cats and trees that Fine cites. Were it any other area of thought, it seems unlikely we would be sympathetic to preposterous arguments.

It seems to me that a better explanation is a ‘snowballing’ theory of sexual difference. Sometimes very slight differences in people can be seized upon and exacerbated by the way that we attribute significance to this difference. Since I work on sports, bear with me as I use it for an example: performance differences between kids in athletics are pretty small and unevenly distributed. All kids, for example, are generally pretty terrible at throwing and catching a ball before they get some practice. Some of us tend to seize upon slight differences in performance as signs of ‘talent.’ These differences get exacerbated over time, as resources, opportunities, motivation, and sense-of-self become invested in what are relatively minor differences in children.

In addition, we know that children’s motivations are extraordinarily subject to social influences, so parental hopes can be transformed, over time, into real physiological difference. If your father and mother think you show tremendous promise as a baseball pitcher or cricket bowler, and you end up spending a lot of hours doing this activity, you can ‘wire’ your nervous system, cultivate your muscles, even shape your shoulder joint (it can be rotated backwards over time) until your body is physiologically better suited for the activity. Your initial ‘talent,’ a slight difference to which is attributed social significance, can become a much greater physical difference over time.

Sexual size dimorphism
A great example of how confounded sex differences can be is size dimorphism between boys and girls. I’d like to briefly explore some of the research on sexual dimorphism as a comparison for some of the differences we find in men’s and women’s brains. Size is one of the most obvious things people point to when they naturalize sex difference: men are bigger than women. And it’s much easier to measure and objectify the difference in size than the difference in brains. Of course, there are lots of confounding examples — again, watching the Australian Olympic swimming trials on TV over the past few days should put this sort of nonsense to rest, but it persists. In fact, the average size of men and women does differ in all societies on which we have data, but the difference itself varies.

Although some researchers argue that human sex size dimorphism is relatively consistent across cultures at around 10% (see Rogers and Mukherjee 1992), a lot of other research points to variability in sexual dimorphism depending upon a society’s overall nutritional supply, labor policies, status of girls, disease profile, and other factors.

When Boïx and Rosenbluth looked closely at data that Franz Boas had assembled on height in Native American groups, they found sexual dimorphism to be more varied than Rogers and Mukherjee’s estimate. They conclude that different levels of nutrition in non-agrarian have unequal effects on men and women; when nutrition is good, non-agrarian men get larger to a greater degree than women (they call them ‘pre-agrarian,’ but I have a problem with this, especially when agrarian and non-agrarian co-existed, and some groups seem to have become ‘less agrarian’ over time). Among their conclusions is that human sexual dimorphism is affected by the advent of agriculture:

The rise in sexual dimorphism that accompanies labor-intensive agriculture may reflect both the societies’ efficient allocation of nutrition [men being more affected by variation in nutrition], and the drop in females’ bargaining position that attends an increased sexual division of labor in which the female invests disproportionately in immobile (to other households) assets such as children. (Boïx and Rosenbluth 28)

This and other research supports the idea that adolescent girls’ size is less likely to be affected by under-nourishment than boys’, a kind of ‘female nutritional resiliency’ that has been found in other research. This would mean that, given no other change, moving from being under nutritional stress to having ample food should lead to an increased difference in the average size between men and women, although both groups would get taller.

The irony is that the advent of farming didn’t necessarily decrease nutritional stress, as foraging Native American populations were sometimes taller on average than farming populations. Whether or not sexual dimorphism would necessarily increase (or decrease) with agriculture was not immediately obvious then; if diet improved, the gap should have increased. If their diet did not improve, men and women should have become closer in average height. Social factors could influence the effects of overall nutrition in a society.

Testing Boïx and Rosenbluth’s thesis, and arguments about changing status for women in Europe, Guntupalli and Baten (n.d.) examined skeletal remains:

We find that the Dark Ages were really dark for women, whereas the Renaissance brought redistribution in favour of women. To be more specific, especially women in the 10th to 12th, and 14th centuries were particularly short in relation to men, whereas the 15th and 16th century women were actually quite tall.

Guntupalli and Baten (n.d.) found that periods of nutritional stress tended to decrease the difference in height between men and women — but not always, suggesting that in some groups, hard economic times that should have decreased the difference led to social effects that increased it (for example, families who were stressed shifting the allocation of scarce resources to boys over girls). In other words, the ‘resiliency’ thesis was not supported by all the data, which may have pointed to a social effect: that hard times were made disproportionately harder for girls due to social values placed on male and female children. Girls in some places disproportionately paid the price in diet for society’s hunger.

For example, in the UK from the 1820s to 1850s, girls disproportionately suffered nutritional stress. According to Guntupalli and Baten (and others), the expected economic benefit from having girls was less in these families, so food was taken away from them and given to male children. Examinations of height divergence following a transition to a free market economy in eastern Europe (for example, in East Germany) suggests that women fared better under socialism in terms of nutrition and height, relative to men (overall, heights have increased, but the gap has increased).

As Guntupalli and Baten (n.d.: 13) summarize:

In all populations, mean male stature is greater than female stature. However, the interesting observation is variation in the degree of stature difference among populations. We would argue that gender differences in stature can be used to answer some important questions: Which societies discriminate females more than others? Which influence do relative female labour participation rates have? Which role role has relative mobility? Does the dimorphism increase or decrease during famine and crisis periods?

Here we have a striking example of a physiological trait that serves as a crucial sex difference, one that couldn’t be more obvious, and yet it varies over time, profoundly affected by mode of production (agriculture or foraging), by historical changes, by variations in attitudes towards the sexes, by economic transitions, and a host of other factors. We know that there are genetic and hormonal contributions to height, and that men are ‘universally’ taller than women (on average, in the groups for whom we have data… etc.), but we also find that this difference is not ‘hard-wired’ or pre-programmed, but emerges from biological, developmental, nutritional, economic, ideological and other factors. In fact, the data we have suggest that it MIGHT even be possible to create conditions under which — with extreme manipulation or conditions that we don’t yet find in one of our populations — the difference might be done away with. MIGHT. (I’m neither advocating this nor suggesting it’s possible for certain, but it is interesting to consider.)

In the West, it seems to me that there’s an enormous difference attributed to a child getting larger depending upon whether it’s a girl or a boy. My nephew, for example, is getting really big; he’s in 10th grade, and he towers over me and is obviously still growing. All the men around get excited at the possibility that he will go far in rugby, as he enjoys playing and seems to do quite well. Needless to say, no one is encouraging him to eat less; quite the contrary, they stack his plate with extra food.

If my niece were going through the same process, I doubt that people would be throwing extra sausages on the barbecue to encourage her to get larger. Nor would they be responding to the size increase by advocating more exercise so that her leg strength could keep up with her size (as they’re doing for my nephew). Could these patterns exacerbate the size dimorphism between men and women? That is, could a smaller difference in size ‘snowball’ into a larger one because of the way that the difference is interpreted and coped with by those around the individual? We know that the gap in average heights between men and women fluctuates, increasing with good nutrition, but might we even encourage the difference beyond this effect?

Statistics about girls and ‘dieting’ always blow me away; there’s always some absurdly high number of girls who claim to be on diets when asked, so I’m as dubious about these self-reported behavioural claims as any other. Some evidence suggests that, above a certain level, increased nutrition does not necessarily lead to people getting still taller. We may have hit a bit of a plateau in height, and even on ‘diets,’ girls might be getting enough nutrition to reach that plateau, but I’m not sure.

Here’s a clear example, however, of a widespread ideology that might be influencing one of the most obvious ‘biological differences’ between men and women. It’s one of the most important differences, and it would seem to be even less liable to developmental influences than the brain’s ‘wiring’ and yet it, too, is subject to variation. In sum, the differences between men and women are likely a moving target, certainly influenced by the indisputable ways in which men and women are different (such as reproductive organs), but also subject to variation.

Fine’s piece is more of a critique of other people’s books about the ‘female brain’ than a discussion of original research, but it’s funny and edgy, so it goes down pretty easy. I’d strongly recommend it. The piece reminded me a fair bit of biologist Anne Fausto-Sterling’s book, Sexing the Body: Gender Politics and the Construction of Sexuality (Amazon). Fausto-Sterling helped to provoke my own interest in neuroscience when I was at Brown University for a year; her book is a great read, and I’m still hoping to get to a copy of her new, Myths of Gender: Biological Theories about Women and Men. If anyone’s interested in how ‘sex’ differences are far more subtle than neurosexists would have us believe, Fausto-Sterling’s work is a great place to start.

Acknowledgments
On this posting, thanks especially to Dan4th at Difference Blog by Dan4th who posted on Cordelia Fine, which I noticed through a trackback. Great post. Dan4th writes: ‘Fine is an author and a biotechnology ethicist. Fine also writes psychology articles for the Australian press. Of particular interest is “Boys cut adrift by dud science” (2007) from The Australian, which takes single-sex-education proponent Leonard Sax to task for suggesting boys can not be taught to be emotionally intelligent.’

All the links I’m providing here at the end of the article were originally put up by Dan4th. Fine, who is at the Centre for Applied Philosophy and Public Ethics at the Australian National University and the University of Melbourne, has a number of other pieces that are well worth a read.

References
Boïx, Carles, and Frances Rosenbluth. 2004. Bones of Contention: The Political Economy of Height Inequality. Working Paper Yale/Chicago. (.pdf of working paper available here)

Davis, Shannon N. 2007. Gender ideology construction from adolescence to young adulthood. Social Science Research 36: 1021–1041. (Abstract here) doi:10.1016/j.ssresearch.2006.08.001

Fine, Cordelia. 2008. Will Working Mothers’ Brains Explode? The Popular New Genre of Neurosexism. Neuroethics 1(1):69-72. (Downloadable here) doi:10.1007/s12152-007-9004-2

Guntupalli, Aravinda, and Joerg Baten. N.d. Measuring Gender Well-being with Biological Welfare Indicators. (.pdf of working paper available here)

Rogers, Alan R., and Arindam Mukherjee. 1992. Quantitative Genetics of Sexual Dimorphism in Human Body Size
Evolution 46(1): 226-234. doi:10.2307/2409817 (abstract here)