Do feminist critics of sex difference research really claim there are no biological sex differences?
The short sweet answer is no. Instead, feminist researchers call on all scientists to take more seriously the question of how radically interactive biology and environment may be, especially when it comes to human behaviour. Today's guest on the HPS podcast is Professor Cordelia Fine, who will be talking about the concept of 'norms of reaction' in reference to sex differences in our brains and our behaviour.
Cordelia is professor of History and Philosophy of Science at the University of Melbourne, and I first met Cordelia when I took her wonderful class, which at the time had the fantastic title "Sex in Science." I love telling people how much I enjoyed sex in science. I'm very excited to have her as a special guest on our podcast today.
Samara Greenwood (00:55): Hi Cordelia. Thanks for joining me today. It is a delight to have you on the podcast.
Cordelia Fine (00:59): Oh, it's a pleasure to be here. Thank you for the invitation.
Samara Greenwood (01:02): Before we discuss the main topic, I wanted to ask you first how you came to be involved in history and philosophy of science, especially as I know yours was not a typical pathway.
Cordelia Fine (01:11): No, it certainly wasn't a very direct route. So, I began my studies in experimental psychology. I took a brief detour into a master's in criminology, and then I came back to psychology for my PhD. Then after my PhD, I came to Australia and I was involved in a number of research projects with philosophers. Then I moved on to work on a project on Neuroethics. At that time, there was this rise in popularity of functional neuroimaging technologies and structural neuroimaging technologies, and of course, they've only gained in prevalence within neuroscience. And I was involved in a project on Neuroethics, which was looking at how are these new technologies changing our conception of ourselves. And at the time, my children were quite young - I had two preschoolers - so I was also reading a lot of parenting books. I noticed that a few of them were starting to draw on findings of sex differences in the brain, using these new technologies and saying - finally we can look into the men and women's brains, and boys and girls brains, and see the actual differences. And suddenly we can understand all the differences between us. I was really interested in this, particularly when they started to mention parts of the brain that I'd studied quite intensely in my PhD. And I thought, no one was talking about sex differences then. That was a nice thing about working at a university. I could look up the research studies that were being cited as evidence and I began to be more and more shocked at the disconnection between what the popular books were writing and what was actually in the scientific literature.
That was the point at which I made the decision to write my second book Delusions of Gender. The intention of the book was to write about how the science was being misrepresented by the popularisers, but in the end it actually became a much more complex and controversial book in the sense that it was criticising the science itself.
And that's what brought me into the area of what we can call feminist critique of science. I actually - subsequently to writing Delusions of Gender - moved to the Melbourne Business School, as part of my strange career path. And there, suddenly I was surrounded by different kinds of people, quite different to philosophers in many ways. All wonderful people though, of course. And then I began to be more exposed to the ideas in economics, which was interested in risk taking and competition. Those are very key concepts in economics. But the economists were becoming interested in testosterone and risk taking and competition and making claims about sex differences due to testosterone in those kinds of behaviours. At the same time, you're interacting a lot more with business communities and hearing some of the popular ideas about why don't women advance in their careers. Is it because they don't have the same drive to succeed or compete? So that was where I came to decide to write Testosterone Rex, which is looking at these arguments about evolution, testosterone, risk taking, competition, and so on. Now it was funny at the time because people would come to the printer and they'd pull out some article that'd just been published that was like, the effects of castration on rats <laugh>. And they'd be like, I think this might be yours, Cordelia <laugh>. So when I moved to the history and philosophy of science programme in the Faculty of Arts here in 2017, it felt like, yes, this is a more natural home for me. <laugh>, though I I really enjoyed my time at the business school. It was a really fantastic experience.
Samara Greenwood (04:41): Oh, fabulous. And then what would you say are your key interest areas in science studies?
Cordelia Fine (04:47): I'm interested in the science of sex differences, particularly in brain and behaviour.
I've always been especially interested in the kinds of characteristics and traits that are drawn on to explain why we have inequalities of power and status.
There's lots of really interesting work on sexuality, physical aggression, et cetera. But, in post-industrial societies, why do we still have so much in the way of inequality? Why do we still have so much segregation in the workplace? So that's often been my interest - interest in the effects of gendered assumptions and stereotypes on theories, methods, hypotheses, interpretations, conclusions, and so on.
I think when you work in this area, you kind of inevitably and quite quickly brush up against these debates about politicisation of science as well. People who do feminist critiques of science are often accused of blurring politics and science or politicising science. And, I think this is a really interesting and important topic. I think these accusations are often, completely misplaced and incorrect. But there is a serious issue here. In my research and in engagement and in teaching I've been thinking about how we can draw on conceptual tools from philosophy of science, thinking about appropriate and inappropriate roles for values in science, to think about where these boundaries are, when are our political values inappropriately intruding in science? I actually talk about that in the subject that you took, which is now called 'Sex and Gender in the sciences.' A bit less exciting title <laughter>. One of the things that we do is we look at some controversial cases and we do it through the angle of articles that evoked controversy and there have been movements, either successful or otherwise, to have the articles corrected or retracted. And the students use what we've learned in the subject to think through and assess what they think the editor should have done, whether they made the right decision or should have done something else.
So part of that is applying what can be quite abstract ideas from philosophy of science to the very real situation of having to make decisions as someone in a decision making role in a scientific journal.
I often leave the last week of the subject clear because, so often, a case will come up during the course of the semester, and then we can analyse it almost in real time. How do they make sure that they're listening to other people's points of view, considering things from all sides, not being dogmatic and disagreeing well? Those are the sorts of sets of skills that I try and integrate into the teaching as well. We are always going to come across ideas that we disagree with, sometimes passionately. How do we deal with those disagreements in a constructive way and in a way that can lead to good decisions?
Samara Greenwood (07:42): Yes, I certainly found that - having taken that class - that there's a real skill to it. That diverse thinking is absolutely essential. Now to turn to the central question of today, which is: could you tell us about a concept in science studies that is perhaps not widely known, but you believe would be of interest to a broader audience?
Cordelia Fine (08:02): So the concept that I wanted to talk about I think is helpful for thinking through another accusation which is sometimes thrown at feminist critics, which is the idea that they're blank slaters. They just think that we all come into the world with empty heads and then we just have gender stereotypes poured into us by outside cultural forces. Again, this is a false caricature, but I think part of the problem here is that there are more and less complicated and nuanced ways of thinking about the role of biology in brain and behaviour. I think the 'norm of reaction' when we apply it to thinking about gender or sex differences is quite a helpful concept. So in a nutshell, the 'norm of reaction' is a very uncontroversial concept in biology, and it refers to the fact that organisms with the same genotype will develop different phenotypes - that is traits and attributes, whether it's height or cognition or number of feathers or whatever it might be. So it will develop these different phenotypes depending on the environment in which it develops. You can think of the 'norm of reaction' as kind of like a map that shows the relationship between the genotype and phenotype across different environments. One helpful way of making it a bit more concrete is to use an example from the zoologist who actually coined the term - he was interested in water fleas. And he observed that they can develop this protective armour from predators, but they only develop that phenotype if they actually develop in an environment in which predators are present. It's gene-environment interaction, nature & nurture interact, right? So, whether you're talking about water fleas, rats, humans - it doesn't matter. No one thinks that the organism's phenotype is completely determined by their genes. The concept of the norm of reaction and how these maps might look a bit different depending on what trait or environment you're talking about can open up some more nuanced ways of thinking about these gene-environment interactions.
Samara Greenwood (10:02): Right. And then, so more specifically in relation to gender and sex differences, how would that work?
Cordelia Fine (10:07): There's some nice terminology and work from the philosopher of biology, Gillian Barker, in a book called Beyond BioFatalism. She drill draws on this concept of the 'norm of reaction' to talk about three different kinds of genotype-environment interactions that can pull us away from this thinking that 'it's just interaction, right?' Well, what kind of interaction? She says there are three. One is what she calls 'conservative interaction'. Here they interact, but it is a way in which the internal causes tend to keep the phenotype very close to a specific developmental outcome, which is kind of evolutionary intended, if you want to think of it in that way. You need very strong or atypical external influences in order to modify that phenotype. Only at the extremes will you not get the phenotype that's intended. So we might think about that from a sex differences point of view. This is captured in expressions like 'boys will be boys', you can try <laughter> to make them more like girls, but their 'true natures' will kind of will out. In fact, there's one researcher in the area who talked about sex differences in the brain as being a bit like being left-handed. You can kind of force somebody to use their right hand, but it's difficult for them, you know, you should just let them use their left hand. Then the second type of interaction is probably more how we tend to think about behavioural characteristics in boys and girls and men and women. This is the idea of 'additive interaction'. Here you allow a bit more influence of environmental factors on how the phenotype develops, but they influence male genotypes and female genotypes to the same degree. So you say, how much nutrition there is in the environment? It's going to influence how tall boys and girls grow on average as a population, but the boys are always going to be taller than the girls and to the same degree. So you have these parallel lines between the male and female phenotypes. Often people are thinking in terms like that kind of additive interaction when they're thinking about sex differences.
But then Barker talks about something which she calls 'radical interaction' which is a nice name. This is where external environmental causes have radically different effects or effects of quite different magnitudes depending on the individual genotypes. So that would mean that, depending on the environment, the size of the sex difference could be quite different or it might disappear or potentially it could even reverse.
One interesting example of this, which when I saw it I was actually quite surprised, was a cross-cultural survey drawing on lower-middle income countries looking at sex differences in adolescence of physical aggression. As you might expect, the overall frequency within these countries varied quite a lot. There are some countries where rates of physical aggression in this group are very high and other countries where it's much lower. But what was also interesting was that the size of the difference was not uniform. It varied from extremely large sex differences in physical aggression to being almost no sex difference at all. That's an interesting example of a kind of radical interaction at the behavioural level. Another example - going a bit more fine grained - is the work of Daphna Joel, a neuroscientist who put forward this idea of 'gender mosaicism'. She was looking at the literature on genetic and hormonal influences on sex differences in the brain, and noting that the sex differences that you observe, and this is an animal research, can be different or opposite depending on the environmental conditions. She argues that because animals naturally live in all kinds of quite varied environments, the result of this is a mosaicism of more male typical, more female typical characteristics in the brain. This gives rise to what she calls these mosaic brains in a kind of multi-dimensional space that can't be reduced either to distinct male or female brains, which is what you'd expect from conservative interaction or a kind of male-female continuum, which is what you'd expect from additive interaction.
Samara Greenwood (14:21): So, it really does support this idea of this radical interaction, the mosaic concept of brain development. Excellent. I was interested in how this idea relates to that idea that supposedly differing levels of testosterone before you're born hard wire us into different ways of thinking.
Cordelia Fine (14:37): Yeah, I think it certainly complicates it. So traditional accounts of sex differences in the brain used the effects of hormones on the genitalia as a kind of model for thinking about sex differences in the brain. Now it has become sort of more complex and nuanced, and I don't think many researchers now would think it very useful to talk in terms of hard wiring. But there's still this kind of legacy of thinking about these effects of early testosterone on the brain. As Rebecca Jordan-Young has pointed out. She did this incredible synthesis of this literature in her book Brainstorm.
Back in the sixties or seventies, there was already evidence that what were being thought of as permanent effects on the brain could actually be undone through quite simple experiences or manipulation. They weren't actually permanent at all.
But one thing she talks about is the scientific models moved onto a softer version, which she describes as a developmental cascade. So this is the idea is that there's a kind of tilt in a particular direction drawing us to particular kinds of experiences. Nature recruiting nurture. Certainly something like this could be going on. But Jordan-Young points out that sometimes that might actually be the developmental story, but the other side of it is that there might be an early push from hormones that's either enhanced or it's actually eliminated, and then development proceeds as if that early push had never actually happened. It's a bit more of an open-ended developmental pathway.
Samara Greenwood (16:12): The title of Rebecca Jordan-Young's chapter I really enjoyed, in which she discusses this concept was called "Trading Essence for Potential." Could you tell us a little bit more about what she means by that?
Cordelia Fine (16:25): She's challenging this standard story that I've described. Like, either these kinds of permanent effects or these developmental cascades, and pointing out that development is a lot more open-ended than this. At each stage of development the organism, the individual, is at a particular state, then there's this interaction and then on to the next state and so on. One way to think about it is to draw on the work of another neuroscientist who comes from a feminist perspective, Lise Eliot. She was talking about this in relation to physical aggression. So there are clear sex differences in physical aggression, and particularly at the most serious forms of physical aggression. Not withstanding that I've mentioned that the size of that difference can be surprisingly variable. And she talks about this idea that it does seem very plausible that there's some kind of early biological tilt, whether it's prenatal testosterone or something else, it's not completely clear, but let's say for the sake of argument it is prenatal testosterone. But then, if you think about this in terms of this initial state it's clear that what you see is most children starting at a sort of relatively high rate of physical aggression when they're very young, then this reducing. Then there's a small number of boys and even smaller number of girls who kind of maintain those higher levels. You can think of that in terms of this early biological tilt that can make you more likely to develop along a particular kind of developmental trajectory, being someone who does not control impulses to behave in physically aggressive ways. But, for the majority, that's not happening. In that sense, most boys end up quote unquote "like girls" in being low in physical aggression. That would be an example of a different way of thinking about it.
So rather than there's a kind of 'seed of physical aggression' in every man that has to be suppressed throughout their lifetimes. There are a few for whom that will be their developmental trajectory, but for others - there's not something that has to be continually suppressed by culture.
Samara Greenwood (18:49): Yes. Why do you feel the concept of 'norms of reaction' is important more broadly?
Cordelia Fine (18:57):
It helps us get away from the idea that people who are criticising the standard or popular story are saying either that sex differences don't really exist, or that hormones don't really have an effect. Hopefully it's clear now that's not really what the story is.
Of course hormones are having an effect, but the question is, where does that effect fit into a whole developmental picture? And yes, sex differences exist, but what would they be in different circumstances with a different developmental history and in a different environment? Those are the different scientific questions that we can be asking.
What sends people on the kind of developmental journey towards traits that we actually want to encourage? And which ones send them on a journey towards traits we don't want to encourage? I think that's one reason why it's important.
And, it really opens our minds to thinking about what we see now, in our current particular context, is in a particular moment of time. That's one of the points that Jordan-Young makes really nicely in her book. She goes from like the nitty gritty of rat sex <laugh> right through to educational achievement in the US. We've seen reversals over the past, 40 or 50 years, where we used to have men getting the majority of degrees. And now in the US and Australia, we actually have women outnumbering men in the number of university or college degrees. The point being that, when you change the environment, you can see quite striking changes in patterns of behaviour and achievement. And so to just be a little bit more open minded in terms of what we might see in the future and what aspects of the environment make a difference and to be scientifically open-minded as well.
I think one thing that Jordan-Young says really nicely, is the way she describes the point of her book. It's not to answer questions, but to question answers. Which I think is a really nice way of putting it.
Samara Greenwood (21:05): Yes, absolutely. So I would like to thank you, Cordelia, for joining us on our first season of the podcast. It has been fantastic to talk with you today.
Cordelia Fine (21:14): Thanks for having me, and I look forward to hearing the other episodes.
Samara Greenwood (21:16): Thanks.
Samara Greenwood (21:19): Thank you for listening to the first season of the HPS podcast, where we discuss all things history, philosophy, and social studies of science. To learn more, check out our website at www.hpsunimelb.org. There you can also find links to our blog, Twitter, Facebook, and Insta, as well as show notes for today's topic. I'm Samara Greenwood, and my co-producer is Indigo Keel. We look forward to having you back again next time.