Skip to content

When you choose to publish with PLOS, your research makes an impact. Make your work accessible to all, without restrictions, and accelerate scientific discovery with options like preprints and published peer review that make your work more Open.

PLOS BLOGS The Official PLOS Blog

How Psychology and Neuroscience Get Sex and Gender Wrong : Neuroskeptic Goes In-Depth with Cordelia Fine

1-tJgrp4WFUzuLxZotboDaUgHas neuroscience proven that men and women are born different? Or are male brains and female brains mostly similar? Is there even such a thing as a ‘male brain’? And how should scientists approach these questions?

To find out I spoke to Cordelia Fine. Fine studied psychology at Oxford and at University College London, and she’s now a Future Fellow at the Melbourne School of Psychological Sciences and an Associate Professor at the Centre for Ethical Leadership at the University of Melbourne in Australia. Alongside her academic work, Fine has published two books for a general audience, A Mind of Its Own and Delusions of Gender. The second book dealt with the issue of sex and gender in psychology and neuroscience, the theme of this interview.

This is the third in my series of interviews for PLOS Neuro as Contributing Editor! If you missed them, check out my interviews with Srivas Chennu and Michael Corballis. I have a regular blog over at Discover Magazine called Neuroskeptic.

NS: Back in 2010 you published Delusions of Gender (my review), a book in which you suggested that the evidence for innate psychological differences between men and women is much weaker than is generally believed. How was your book received?

Cordelia_FineCF: Obviously nobody finishes a book on this topic and, laying down their pen, thinks, “Yep, I reckon everyone will agree with this.” But I’m very happy with the attention the book has enjoyed, both in the scientific and popular domains.

In August, you along with three colleagues published a paper called ‘Recommendations for sex/gender neuroimaging research’. In this article you provide a set of guidelines for neuroscientists who are interested in researching sex differences in the structure and function of the brain. What inspired you to write that piece?

We wanted to write a constructive paper offering recommendations intended to be helpful to researchers, editors, reviewers and even science communicators. At the heart of the paper is the argument that researchers (and others) need to pay greater attention to what gender scholarship has revealed about the nature of sex/gender, which is often quite different to the implicit ‘gender essentialist’ assumptions that often seem to guide research design and interpretations in current research.

Gender essentialism is the belief that the psyches of females and males are highly distinct, and the differences between the sexes are natural, fixed and invariant across time and place.

In the ‘Recommendations’ paper, you suggest improvements for sex/gender neuroimaging research. Some of these recommendations are quite general. For example, you say that sample sizes ought to be larger to avoid the problems of underpowered studies, and you also discuss preregistration of protocols to avoid the problem of “fishing” for positive results. These problems have been noted across science – do you think that they’re especially serious in sex/gender neuroscience?

These two issues are certainly general to behavioural science, but there are a few reasons they may be especially acute when it comes to this area of research.

With regards to sample size, different implicit models of sex/gender and the brain will give rise to different intuitions or assumptions about what is an adequate sample size. According to implicit essentialist assumptions, there are there are distinctively different ‘male’ and ‘female’ brains. But non-human animal research has shown that biological sex interacts in complex ways with many different factors (hormones, stress, maternal care, and so on) to influence brain development. Because of the complexity and idiosyncrasy of these sex influences, this doesn’t give rise to distinctive female and male brains, but instead, heterogeneous mosaics of ‘female’ and ‘male’ (statistically defined) characteristics.

Tel-Aviv neuroscientist Daphna Joel has a nice way of describing the implications of this. It means that while certain brain characteristics may be statistically more common in human males than females, knowing someone’s sex doesn’t enable you to predict the particular array of ‘male’ and ‘female’ brain characteristics that person will have.

As for publication bias for positive findings, this has long been argued to be particularly acute when it comes to sex differences. It’s ubiquitous for the sex of participants to be collected and available, and the sexes may be routinely compared with only positive findings reported. As Anelis Kaiser and her colleagues have pointed out, this emphasis on differences over similarities is also institutionalized in databases, that only allow searches for sex/gender differences.

Does academic research on sex and gender itself affect the way that men and women behave and think, by changing public attitudes?

Thinking in a ‘gender essentialist’ way has been linked with a number of negative psychological consequences, including greater endorsement of gender stereotypes both in relation to self and others, stereotype threat effects, greater acceptance of sexism, and increased tolerance for the status quo.

It’s a plausible hypothesis that the conclusions of scientific research will influence cultural beliefs about the sexes. (In fact, faux scientific articles are commonly used in laboratory psychology experiments as a way to temporarily modify these beliefs.)

269652-brains
Researchers found increased connectivity in males from front to back within one hemisphere (upper) and left to right in females (lower).
Credit: Ragini Verma, PhD, Proceedings of National Academy of Sciences

An interesting recent case study of this process looked at media and social media responses to a study published in PNAS reporting sex differences in brain connectivity (and speculating on their functional implications).

In their content analysis, published in PLOS ONE, Cliodhna O’Connor and Helene Joffe concluded that traditional gender stereotypes were projected onto the scientific findings, which in turn were taken to bring legitimacy to those beliefs.

journal.pone.0110830.g003 (1)
FIGURE 3: Prevalence of causal attributions for sex difference across the datasets.
doi:10.1371/journal.pone.0110830.g003

One of the points we make in our Frontiers article is that brains and behaviour reflect a biosocial ‘entanglement’ – and that the outputs of neuroscientific investigations of female/male differences actually become part of that entanglement. The motivation for the Frontiers paper in part came from an earlier article we wrote for Trends in Cognitive Sciences, where we argued that the outputs of research guided by updated developmental models of sexual differentiation of brain and behaviour bring opportunities to change cultural assumptions about the sexes.

By way of a simple example, neuroimaging research conducted from an implicitly gender essentialist frame tends to take single ‘snap-shot’ comparisons of the sexes – an approach which is guaranteed not to produce any data that can challenge the notion of fixed, universal male versus female neural essences.

In our Frontiers paper we highlight, by contrast, the possibility of drawing on the principles of the contingency of female/male differences, and entanglement, to challenge the stabilities of observed differences and similarities; for example, by experimenting with context, or population.

DelusionsPinkMuch has been said about the issue of women in science lately. Can the psychology and neuroscience of sex and gender inform this conversation?

The reason why it’s important to get the research in this area right is that it influences conversations about all forms of sex inequality. I certainly think behavioural science can inform these conversations, with the caveat that the neural correlates of ‘capability for a successful scientific career’ and ‘inherent drive to work 80 hour weeks in the lab’ won’t be identified any time soon.

You say that “researchers (and others) need to pay greater attention to what gender scholarship has revealed about the nature of sex/gender.” What could be the solution to this problem? Do we need (more) inter-disciplinary collaborations between neuroscientists and other researchers e.g. gender scholars?

I think this is one good option, although of course this would be more likely when investigation of sex/gender influences are motivated a priori, rather than analysed and interpreted post hoc. There are also some great examples of what you might call within-person interdisciplinary collaborations – researchers whose expertise and interests span across neurobiology and gender scholarship. But more simply, the hope was for our article to be part of that solution, by providing a concise and practical overview and recommendations.

You say that “neuroimaging research conducted from an implicitly gender essentialist frame tends to take single ‘snap-shot’ comparisons of the sexes – an approach which is guaranteed not to produce any data that can challenge the notion of fixed, universal male versus female neural essences” Do the same problems exist in neuroscience beyond the question of gender? I mean: do you think that the neuroscience of (let’s say) race, or sexual orientation, are also prone to essentialist assumptions that lead researchers to ask the wrong kind of questions?

I think that’s a very good question. Whenever neuroscientists are comparing categories, it will probably be helpful to consider what “kinds of kinds” (as Nick Haslam has put it) are involved: for instance, are there sharp category boundaries and discontinuities, or a seamless continuum.

Neuroskeptic is a British neuroscientist who takes a skeptical look at his own field, and beyond.neuroskeptic

On Twitter @Neuro_Skeptic

 

Discussion
  1. This article seems to be implying – forget biological research, based on empirical data gathering, and direct biological observation and just pay more attention to gender ideologues from the social (non) sciences arena.

  2. Genealogical Correspondence of Mushroom Bodies across Invertebrate Phyla http://www.sciencedirect.com/science/article/pii/S096098221401358X appears to link sex differences in the brain to nutrient-dependent RNA-directed DNA methylation and RNA-mediated events. The RNA-mediated events link amino acid substitutions to cell type differentiation in all cells of all individuals of all species via conserved molecular mechanisms. For example, epigenetic effects of chemosensory input support the claim that “Feedback loops link odor and pheromone signaling with reproduction.” http://www.sciencedirect.com/science/article/pii/S0092867405009815

    An earlier work, which was also co-authored by Strausfeld, linked the microRNA/messenger RNA balance to RNA-mediated cell type differentiation. Homology versus Convergence in Resolving Transphyletic Correspondences of Brain Organization http://www.karger.com/DOI/10.1159/000356102

  3. Agreed. If you include empirical data, you are forced to admit that all cell type differentiation is nutrient-dependent and RNA-mediated. Indeed, everything occurs in the context of the metabolism of nutrients to species-specific pheromones that control the physiology of reproduction in species from microbes to man.

    You are then stuck with accurate representations of biologically-based cause and effect linked to cell type differentiation and sex differences in brain development via works from Vitkup’s group.

    Genotype to phenotype relationships in autism spectrum disorders http://dx.doi.org/10.1038/nn.3907

    Long-term phenotypic evolution of bacteria http://dx.doi.org/10.1038/nature13827

    The pseudoscientific nonsense of social science was first eliminated by what was known about RNA-mediated events when we linked them from yeasts to mammals in our 1996 Hormones and Behavior review. From Fertilization to Adult Sexual Behavior http://www.hawaii.edu/PCSS/biblio/articles/1961to1999/1996-from-fertilization.html

    That means someone has some explaining to do. The problem is that they still can’t explain anything about biologically-based cause and effect because they are stuck with theories based on definitions and assumptions.

    They have no biologically-based model and no model organisms to support their claims. It’s as if they invented — from scratch — whatever they think supports anything they’ve ever claimed.

    Feynman addressed that in this short video: https://www.youtube.com/watch?v=HtMX_0jDsrw

  4. There’s an abundance of research showing that there is an “organizational” period during prenatal development, during which exposure to androgenic hormones (testosterone and DHT) causes masculinization of the brain. In the absence of those hormones, the brain develops along female lines instead. This is simply an extension of the same processes that drive physical sexual development. Whatever happens during that organizational period has lifelong effects on social and sexual behaviour, and also affects the way the brain responds to externally administered hormones.

    This is something that’s been demonstrated in a large number of mammal and bird species, so it’s absurd to argue that there aren’t significant hardwired differences between male and female brains in human beings too, that have lifelong effects on our behaviour, and indeed our internal sense of who we are and which gender we identify as too. That is why, in instances where male babies with damaged genitals have been surgically reassigned to female (e.g. the David Reimer case), there is generally a very poor outcome, with a high percentage spontaneously adopting a male gender identity later in life despite being raised as girls.

  5. I wrote:
    The pseudoscientific nonsense of social science was first eliminated by what was known about RNA-mediated events when we linked them from yeasts to mammals in our 1996 Hormones and Behavior review. From Fertilization to Adult Sexual Behavior http://www.hawaii.edu/PCSS/biblio/articles/1961to1999/1996-from-fertilization.html

    The co-author of our review exposed the John/Joan case that you just mentioned. It was a textbook example of ignorance that led to the death of both boys.

    What’s been demonstrated in all species of vertebrates and invertebrates is that sex differences in cell types are nutrient-dependent and pheromone-controlled via the conserved molecular mechanisms of RNA-mediated cell type differentiation.

  6. Sex specific behavior is found in non social mammals and sexuality is not strictly linked to the sex perceived by the social environment. So how can the differences in the brain be purely caused by gender, which is a social category?
    Then you might say, of course, the same neuronal substrate acts differently in the presence of different hormonal states causing sex differences but the brain itself isn’t different. That doesn’t get you far because brain state, hormonal or otherwise, influences plasticity leading to sex specific adaptations in development and experience.
    Obviously research needs to be done thoroughly and one needs to refrain from labeling one sex as ‘better’ than another in whatever process is being studied. Objectivity is number one priority. However, I’d by quite surprised if there were no traits that are consitently different between male and female brains.

  7. Excellently put, Whothehell!
    Science should be blind to ideologies, not follow them and _pretend_ to be impartial.
    Ideological pressure has always been an issue, in any time and place, but to use it so shamelessly, with so much vested interest and careerism is just disgraceful.

  8. Boy, are all the previous comments ever crappy! Assertions of brain and behavior stuff that has not been proven. Human pheromones?! Wow. The “cell differentiation” crowd don’t seem to understand what these functional neuroimaging experiments are. I’m no fan of them myself. But they are not “social science”. It was a good interview, very interesting stuff. I’ve read her excellent Delusions of Gender. It would’ve been better if how the “single snapshot” approach means those researchers can never find the *variation* that fuzzies-up the seemingly crisp line between supposedly male and female responses was made more clear.

  9. I’ve never really understood that testosterone in the fetal brain thing. Do brain cells actually have receptors for testosterone? I mean other than the hypothalamic part that monitors the testosterone levels in the blood.

  10. Yes, brain cells do have hormone receptors! If you have abnormally low testosterone (as I do), then you’ll know that the brain is a highly hormone-responsive organ, and if your hormone levels aren’t in the normal range, it affects all sorts of things: your energy levels, your mood, your ability to concentrate and think clearly. In my case, if my testosterone remains low for a substantial period of time, I start getting neurological symptoms as well – tinnitus, vertigo attacks and acephalgic migraines. Steroid hormones play a crucial role in maintaining brain health and in the normal functioning of the brain, to a far greater extent than most people realise.

    The other thing is that hormones play two distinct roles as far as the brain is concerned: early in life, they have an “organizational” effect, in which they cause brain development to occur as male or female; in adulthood, they have “activational” effects, in which the brain circuitry that drives sex-specific behaviour (that was laid down during the organizational phase), is brought to life. I’m not sure whether I can post links here, but there’s a very good free to view paper that explains how this works:
    “Effects of prenatal androgens on rhesus monkeys: A model system to explore the organizational hypothesis in primates”
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3146061/

    From that paper, you can see how it’s quite easy to produce animals with a brain that doesn’t match their biological sex, just by administering external hormones to the mother during pregnancy.

    I suspect that the main reason this is not very widely known is because of a pharmaceutical industry blunder that took place between 1940 and about 1980, as a result of which millions of pregnant women were administered high doses of synthetic hormones, some with testosterone-blocking properties (DES and ethinyl estradiol), and others that turned out do have quite strong androgenic effects on female fetuses (danazol and first generation progestins). From what I’ve seen of the effects of DES, there must be a lot of people alive today who, unknown to themselves, have undergone at least some cross-sex brain development as a result. I think this is the real reason why we’re suddenly seeing a lot of stories in the news about men wanting to become women and vice versa.

Leave a Reply

Your email address will not be published. Required fields are marked *


Add your ORCID here. (e.g. 0000-0002-7299-680X)

Back to top