Having clarified, in the previous blog post, the understanding of the concept of “feminist theory” on which Project FEMSAG is based, I now continue with a conceptual primer on the second half of the project title “Feminist Theory After Sex and Gender”. In other words, let’s talk about “sex” and “gender”.
As it happens, my current understanding of these concepts has evolved since embarking on the project and so is no longer the one that formed my point of departure as I wrote the grant application for FEMSAG. But since my current understanding has taken shape while battling with the difficulties tied into my previous views, I’ll present my current view through a description of how it has evolved. As is so often the case when clarifying the use of contested terms, it will be useful to frame the discussion of “sex” and “gender” within the history through which they emerged as common currency within gender research and feminist discourse. I will therefore begin by sketching an intellectual history of how the sex/gender distinction passed from mid-20th century sexology into early 2nd wave feminist theory. From there I proceed to outline what currently seems to be the dominant view within feminist science scholarship, at least in that part of it that deals particularly with research on sex/gender and the brain, which is also the view that formed my point of departure when I conceived Project FEMSAG: the view that it is practically impossible to distinguish between sex and gender. In the last two sections, I explain why I disagree with this view and how I believe the distinction could be drawn without sacrificing the intuitions that motivate the no-distinction view.
This text has, in the course of writing it, vastly outgrown the normal format of a blog post and rather taken on the proportions of a scholarly article. I hope it will nonetheless turn out both an accessible and rewarding read for the interested and curious layperson.
The origins of the sex/gender distinction in mid-20th century sexology
Although it is feminist theory that has contributed by far the most to the development, refinement and also criticism of the sex/gender distinction, it didn’t originate there. Rather, it was imported by anglophone feminist theorists in the late 1960s and early 1970s from the work of two pioneers of 20th century sexology, namely, John Money (1921-2006) and Robert Stoller (1924-1991).
Money was professor of pediatrics and medical psychology at Johns Hopkins University, Baltimore, from 1951 until his death. At Johns Hopkins, he worked– along with colleagues John Hampson and Joan Hampson – with the clinical care and management of people presenting with unusual reproductive anatomies and physiologies, i.e., people who today are referred to as “intersexed”. Based on their experience with and study of this clinical population, as documented in a series of publications during the 1950s and 1960s, Money and the Hampsons devised a theory of psychosexual development formulated in a novel conceptual apparatus. In a nutshell, their claim was that psychosexual differentiation – i.e., the development of an individual into one of the two psychosocial types “boy”/“man” or “girl”/”woman”, respectively – is more a function of what they called “the sex of assignment and rearing” (i.e., childhood socialization as boy or girl, respectively) than of genetic, anatomical and physiological markers of sex (i.e., chromosomes, gonads, hormones, internal reproductive organs and external genitalia).
It was in order to clarify this hypothesis that Money came up with the novel term “gender role” as a rubric of all the items that he thought co-constitute “boyhood”/”manhood” and “girlhood”/”womanhood”, respectively, as psychosocial types. Gender role, Money & the Hampsons suggested, includes “all those things that a person says or does to disclose himself or herself as having the status of boy or man, girl or woman, respectively”. As such, they reasoned, it covers “sexuality in the sense of eroticism”, but it is also manifest in and through such things as “general mannerisms, deportment and demeanour; play preferences and recreational interests; spontaneous topics of talk in unprompted conversation and casual comment; content of dreams, daydreams and fantasies”.
Stoller, the other key figure behind the development of the contemporary concepts of sex and gender, was a psychoanalyst, Professor of Psychiatry at the UCLA Medical School, and a researcher at the UCLA Gender Identity Clinic. In 1968, he published a monograph titled Sex and Gender: On the Development of Masculinity and Femininity, in which he lays out a theoretical framework reflective of his clinical and research experience with intersex people as well as people who are now referred to as transgender (i.e., people with a strong sense of belonging to a different sex than the one assigned to them at birth). In this work, Stoller built on the work by the Johns Hopkins group, but the conceptual apparatus he devised was both more clear-cut and more nuanced.
In the terminology proposed by Stoller, sex has chiefly “biological connotations”. It is determined, Stoller writes, on the basis of such traits as “chromosomes, external genitalia, internal genitalia (e.g., uterus, prostate), gonads, hormonal states, and secondary sex characteristics”. In most – but certainly not all – cases, the “algebraic sum of all these qualities” serves to locate an individual person “under one of two separate bell curves, the one of which is called ‘female’, the other ‘male’”. Gender, for Stoller, “is a term that has psychological or cultural rather than biological connotations”; it is designated as “masculine” and “feminine”, respectively, and such traits may “may be quite independent of (biological) sex”. While an individual person’s gender is often a mixture of both characteristics, “the normal male has a preponderance of masculinity and the normal female a preponderance of femininity”.
Stoller makes a further distinction of gender between gender identity and gender role, hence a complication of Money & the Hampsons’ original formulation. “Gender identity”, Stoller claims, consists at first in “the knowledge and awareness, whether conscious or unconscious, that one belongs to one sex or the other”; but this core gender identity may be further overlaid and complicated throughout development, “so that, for example, one may sense himself as not only a male but a masculine man or an effeminate man or even a man who fantasies being a woman”. In contradistinction to gender identity, which seems to concern a person’s sense of belonging to one or the other sex, or of being masculine or feminine – hence something pertaining to the person’s “inner life” – Stoller uses “gender role” to denote “the overt behaviour one displays in society, the role which he plays, especially with other people, to establish his position with them insofar as his and their evaluation of his gender is concerned”.
Stoller is thus less explicit than Money & the Hampsons regarding what aspects of overt behaviour are pertinent markers of someone’s gender role. Yet a quick glance at the case histories that form the bedrock of his work make clear what he has in mind. To take but one illustrative example: A four year old intersexed boy (“born with no external penis but with bilateral testes in a bifid scrotum that resembled labia majora and labia minora, and with a perineal urethrostomy”) is described, by his parents’ account, as a “psychologically normal boy”, meaning that he is “rough” and “active”, “enjoys playing football and baseball with his father”, “likes to wrestle and box”, “likes to watch sports on television” and “wants to be a wrestler – big and fat – when he is big”; compared to his stepsister, “who can’t occupy her time by herself”, he can be given a little stick and sent out to play and then will “make everything out of that stick you can imagine”, and so on.
As already noted, for Stoller, “gender” (both in the sense of gender identity and gender role) is “a term that has psychological or cultural rather than biological connotations”, and the traits it subsumes – masculinity and femininity – may also be “quite independent of (biological) sex”. It is not absolutely clear what Stoller means by speaking of gender as having “psychological or cultural rather than biological connotations”, but his presentation in the book’s preface of the theoretical conclusion that he arrived at on the basis of his clinical work may give us some clues as to what he has in mind. Those aspects of a person he refers to as “gender” he believes to be “primarily culturally determined”. This is to say that a person’s gender is something that is acquired primarily through a “learning process [that] starts at birth”:
This cultural process springs from one’s society, but a sense of this is funneled through the mother, so that what actually impinges upon her infant is her own idiosyncratic version of society’s attitudes. Later, the infant’s father, siblings, friends, and then gradually the whole of society present upon his developing identity.
For Stoller, then, it is such a theoretical account of gender development that best explains how it is possible that – as indicated in the many clinical case histories he cites in the book – each of sex and gender “may go into its quite independent way”.
It should be noted that, although his major theoretical emphasis is on the significance of socio-environmental influences on the determination of a person’s gender, Stoller is far from disregarding entirely a possible contribution from what he calls “biological forces”, by which he means “energy from biological sources (such as endocrine or CNS [i.e., central nervous system, i.e., the brain] systems), which influences gender identity formation and behaviour”. He suspects such forces may be at work in some intersex cases where the intersex condition is not discovered until puberty, such as in people whose anatomy appears at birth unremarkably as of one sex rather than the other and who are henceforth raised in the gender “appropriate” to that sex, yet who consistently act in line with the “other” gender. Nevertheless, his most considered opinion seems to be that it is only in rare cases that biological forces can be credited with such a powerful influence on gender identity. As such, they are exceptions to what he takes to be the general rule, namely, that “postnatal psychological forces play the most powerful and obvious part in creating gender identity, with genetically controlled biological forces silently augmenting this process”.
The uptake of the sex/gender distinction in 2nd wave feminism
When anglophone feminists of the 2nd wave began using the terms “sex” and “gender” around 1970, it was largely Stoller’s conceptualization that formed their point of departure. Kate Millett’s Sexual Politics, first published in 1970, is probably one of the first instances of a feminist theorist explicitly drawing (upon) the sex/gender distinction. In this book, Millett argues that patriarchal rule – the rule of men over women, and of older men over younger men – is set up and maintained through a sex-differential positioning with regard to the three parameters she calls status, temperament androle, respectively.
“Status”, in Millett’s terminology, is that with respect to which patriarchy positions men and women as superior and inferior, respectively. “Temperament” is Millett’s term for personality or personal character, which under patriarchy develops “along stereotyped lines of sex category (‘masculine’ and ‘feminine’), based on the needs and values of the dominant group and dictated by what its members cherish in themselves and find convenient in subordinates: aggression, intelligence, force, and efficacy in the male; passivity, ignorance, docility, ‘virtue’, and ineffectuality in the female”. Lastly, what Millett calls “sex role” comprises a “consonant and highly elaborate code of conduct, gesture and attitude for each sex”, which “assigns domestic service and attendance upon infants to the female, the rest of human achievement, interest, and ambition to the male”.
Dismissing, on account of lacking evidence, “the thesis that the present social distinctions of patriarchy (status, role, temperament) are physical in origin”, Millett turns to “[i]mportant new research” that, in her estimation, “gives fairly concrete positive evidence of the overwhelmingly cultural character of gender, i.e. personality structure in terms of sexual category”. Not only is this the first time in the book Millett uses this very term, “gender”, but the mentioning is immediately followed by a sequence of paragraphs containing expositions of, and extensive quoting from, Stoller’s Sex and Gender as well as a 1965 paper by John Money, both invoked as “expert witnesses” to the distinguishability of sex and gender and to the power of culture to influence the shape of the latter.
The distinguishing feature of Millett’s account – being a feminist one – is of course that she is much more explicit about the political nature of the social relations and processes whose output is the systematic inculcation of “masculine” and “feminine” personality traits in boys and girls, respectively. This comes out when she adds status and worth to the elements contributing to gender development under patriarchy: “Implicit in all the gender identity development which takes place through childhood is the sum total of the parents’, the peers’, and the culture’s notions of what is appropriate to each gender [sic] by way of temperament, character, interests, status, worth, gesture and expression”. The political dimension signalled by the mentioning of status and worth as contributors to gender development is at best implied, if not altogether obliterated, in Stoller’s and Money’s respective accounts.
Ann Oakley’s Sex, Gender and Society, first published in 1972, provides another instance of early 2nd wave feminist work drawing and elaborating on Stoller’s and Money’s sex/gender distinction. Compared to Millett’s Sexual Politics, with its characteristically polemical flair, Sex, Gender and Society reads more like a scholarly dry review of the scientific evidence for biological vs. social conditioning of sex differences in personality traits, cognitive abilities, sexuality, social roles and so on, with a rather pronounced emphasis on the significance of social conditioning (Oakley is, after all, a sociologist by training). The chapter titled “Sex and Gender”, identified by the author in the introduction to the book’s 2015 reissue as the “core of the book”, opens with the declaration that “’Sex’ is a biological term: ‘gender’ is a psychological and cultural one”. What we are to understand by this, Oakley explains, is that being a man or a woman, boy or girl – i.e., being gendered in addition to being merely sexed – “is as much a function of dress, gesture, occupation, social networks and personality, as it is of possessing a particular set of genitals”.
One body of evidence supporting this claim, reviewed in previous chapters, is drawn from anthropological research showing “wide variation in the way different cultures define gender”. In other words, while there is near cross-cultural consistency in the ways in which the male/female distinction is drawn, and also in the use of that distinction as the basis for ascription of gender, the ethnographic record shows ample cross-cultural diversity in understandings of gender, i.e., how the masculine/feminine distinction is drawn.
The other body of evidence warranting a conceptual distinction between “sex” (understood as biological) and “gender” (understood as psychological and cultural) comes, according to Oakley, from Stoller’s and Money’s work on intersexed people, which she then proceeds to expound on for the remainder of the chapter. The importance of this work, according to Oakley, is that it “show[s] that someone who is neither male nor female can be masculine or feminine – just as masculine or just as feminine as those who are biologically normal”. If sex and gender are thus able to vary independently of one another, and if each may thus “go into its quite independent way” during development, as Stoller had argued, this counts for Oakley – just as it did for Stoller – as proof that they must be “two separate entities”.
In the subsequent chapter, “The Learning of Gender Roles”, Oakley then proceeds – on the basis of the Stoller/Money thesis of sex and gender as conceptually distinct – to defend, with reference to studies of non-clinical populations by sociologists, the theoretical claim concerning the cultural (as opposed to the biological) determination of gender. Here, she cites studies showing how parents handle their infants and respond to them in gender-stereotyping ways from as early an age as three weeks, how this socialization continues into later stages of childhood (such as through the gender-labelling of toys and activities), how it is enforced more vigorously on boys than on girls in certain stages (one is punished more severely for being a “sissy boy” than a “tomboy”), how it is further augmented by the wider culture in terms of textbooks used in primary schools, the gendered iconography proliferated through mass media, economic regulations sanctioning certain family arrangements and discouraging others, and so on. So overwhelming is the power of such influences combined, Oakley concludes, that “children’s gender roles and identities…are very largely a product of culture”, indeed, that they “ha[ve] no biological origin”.
The sex/gender distinction in recent feminist science studies
Since the early conceptualizations of the sex/gender distinction – originating with Money and Stoller, then taken up and elaborated upon by 2nd wave feminists – feminists have grown increasingly wary of treating “sex” and “gender” as distinct concepts. There are several trajectories of theory that have led to this uneasiness. One is that of queer theory, spear-headed by Judith Butler’s famous claim that what is customarily referred to as sex as distinct from gender is really an “effect” of certain gender norms that work to sanction heterosexuality as the only culturally legitimate form of sexuality and genetic family relations as the only culturally legitimate form of kinship. From the observation that even the notion of “sex” as a chromosomal, anatomical or hormonal fact about the human body “prior to” or “outside of” the culturally variable framings of “gender” (i.e., ideas of masculinity and femininity) is a historically dateable notion, Butler argues that “perhaps this construct called ‘sex’ is as culturally constructed as gender; indeed, perhaps it was always already gender, with the consequence that the distinction between sex and gender turns out to be no distinction at all”.
Another branch of feminist thought which has recently put increasing pressure on the idea of “sex” and “gender” as distinct concepts (or, in Oakley’s phrase, as “separate entities”), although perhaps not with the aim of showing that it is really “no distinction at all”, is a new breed of feminist science scholarship known as “neurofeminism”. This is a profoundly interdisciplinary research field involving workers trained in the biological sciences (genetics, developmental biology, neuroscience etc.), the social sciences (psychology, sociology, anthropology etc.) and the humanities (media studies, literary studies, philosophy) aiming to “critically examine neuroscientific knowledge production and to develop differentiated approaches for a more gender adequate neuroscientific research”.
A number of these scholars have adopted the convention of not referring to “sex” and “gender” separately but always conjointly as “sex/gender”. This terminological device, as well as the rationale for it, was pioneered by Anelis Kaiser and colleagues in a 2009 review paper titled “On sex/gender related similarities and differences in fMRI research”. In it, Judith Butler’s position is glossed as the claim that “a clear-cut distinction between biological sex and social gender does not exist”, and it is argued that neuroscientists’ realization of neuroplasticity, i.e., the ability of experience to drive and shape development of brain structure and circuitry throughout life, may have vindicated this claim. Such findings have made it “increasingly evident”, they claim, that “biological components of reported differences in brain structure and functions cannot be separated from social experience” and may help explain “the close interrelation between sex and gender in each individual brain”. It is in order to highlight the bearing that this intertwinement of biological with social factors must have on the interpretation of differences between women’s and men’s brains showing up in brain imaging studies that Kaiser et al. propose to “use the double term sex/gender whenever possible”.
This argument needs some unpacking. It proceeds in two basic steps. First, although it is not stated explicitly, it seems to be assumed that the content of the original concepts of “sex” and “gender” (as worked out by Money, Stoller and the 2ndwave feminists) is that “sex” denotes those inputs to an individual’s development as a man or a woman that are biological in nature, while “gender” denotes those inputs to an individual’s development as a man or a woman that come from that individual’s socio-cultural environment. In other words, the sex/gender distinction is understood as but a specific instance of the more general biology/culture distinction, i.e., what is known more colloquially as the nature/nurture distinction.
Second, it is noted that the biology/culture (or the nature/nurture) distinction doesn’t work in practice, since (as is shown by neuroplasticity) it is pointless to try to disentangle absolutely the developmental contributions of “biology” from those of “culture” to a given difference of brain structure or function between, e.g., men and women. It is concluded that, since no clear-cut distinction exists between the biological and the cultural contributions to observable developmental outcomes (such as brain differences between men and women), nor can there be one between sex and gender.
This conclusion is then echoed by, among others, the editors of the 2012 article collection Neurofeminism: Issues at the Intersection of Feminist Theory and Cognitive Science, who cite “the difficulty of distinguishing between sex and gender in discussions of the brain”; by Rebecca Jordan-Young and Raffaella I. Rumiati, who argue in their contribution to that collection that “’sex’ and ‘gender’ are, in practical terms, inseparable”; and by Gina Rippon who, in her 2019 book The Gendered Brain: The new neuroscience that shatters the myth of the female brain, cites “[o]ur emerging understanding of how much the brain can be influencd by social pressures” as a reason why “it [is] getting harder and harder to sustain this neat distinction between sex and gender”. It was even prefigured by Melissa Hines – neither self-consciously nor officially recognized as part of any feminist scholarship tradition – in her 2004 book Brain Gender, when she denies the possibility of distinguishing meaningfully between “sex differences” and “gender differences”, on the grounds that “the distinction between biological and social influences is in some sense false”.
The sex/gender distinction in FEMSAG, then and now
When I wrote the grant application for Project FEMSAG back in 2015, I was thinking broadly along those very lines detailed in the previous section. In other words, I thought of the sex/gender distinction as somehow homologous with the biology/culture or nature/nurture distinction. For this reason, I considered it an embarrassment on the part of the feminist science studies community that one hadn’t yet, in the face of overwhelming empirical evidence and theoretical arguments undermining the nature/nurture distinction (much of it developed within feminist science scholarship itself), come up with a way of dispensing with the sex/gender distinction altogether (as suggested by Butler). That is, if everyone seems to concur with Melissa Hines’ general verdict that “the distinction between biological and social influences is in some sense false”, as well as with the premise that “sex” denotes (if anything) “biological” influences (i.e., “nature”) and “gender” (if anything) the “social” or “cultural” influences (i.e., nurture) on development, why not come up with something else than continuing to use the same old terms, albeit with the caveat that they are practically indistinguishable, as signaled by gluing them together with a slash? This is what I wrote:
Although many of [the neurofemininist scholars] signal their commitment to strong nature-nurture interactionism by employing a newly agreed upon convention of always writing “sex/gender,” this very convention comes across as a promissory note on a more thorough theoretical elaboration yet to be undertaken.
Accordingly, I conceived of Project FEMSAG partly as a contribution to a theoretical elaboration of the nature/nurture problematic that would result in so decisive an undermining of the sex/gender distinction as to obviate the need to retain even the slightest terminological trace of it. Whence the main title of the project: Feminist Theory After Sex and Gender.
As anticipated at the outset of what is now becoming increasingly difficult to call a “blog post”, this is no longer the way I think about the sex/gender distinction. That is, I no longer think that the sex/gender distinction will – or should – disappear, nor even be made unworkable in practice, along with the nature/nurture or biology/culture distinctions, although there may be other, independent reasons for dispensing with it (but this will not be my concern here). The reason is that the sex/gender distinction and the nature/nurture distinction pertain to different orders of questioning. To explain what I mean by this, it is necessary to return once again to the Money/Stoller and early 2nd wave feminist formulations.
When Money and Stoller introduced (each in their unique way) the terminology that distinguished “gender” from “sex”, it was out of a need to designate an attribute (or set of attributes) of a person that is distinct from (a) certain other (set of) attributes, and to convey the fact – as they had observed clinically – that the two (sets of) attributes may develop quite independently of another in a given person.
The attribute (or set of attributes) designated with the term “sex” comprised, in this thinking, the physically observable or detectable traits relating to the person’s reproductive anatomy and physiology (such as internal and external genitalia) as well as the person’s sex-related karyotype (i.e., whether the person’s 23rd chromosome pair is an XX or an XY, or some variant of one or the other). The attribute (or set of attributes) designated with the term “gender”, as Stoller emphasized, had “psychological or cultural connotations”, and comprised an individual’s sense of belonging to one or the other (or none) of the sexes (male or female) as well as – in Money and the Hampsons’ formulation – “all those things that a person says or does to disclose himself or herself as having the status of boy or man, girl or woman, respectively”. In short, what Stoller and Money et al. wanted to capture with the term “gender” were of a psychological order: an inward sense of belonging to one sex or another, combined with a certain sex-typed behavioural disposition as expressed outwardly in a certain sex-typed behavioural style or in the assumption of a certain sex-typed repertoire of roles. In Millett’s elaboration, it is emphasized that gender is a differential with respect to “personality structure” or “temperamental trait”, in addition to role and status, and that in situations of patriarchal rule, males are much more likely to have the stereotypically “masculine” profile on these parameters, whereas females are more likely to exhibit the stereotypically “feminine” traits.
Considering the sex/gender distinction from this perspective, I don’t find it particularly difficult – neither in theory nor in practice – to distinguish between “sex” and “gender”. Indeed, it is no more difficult to make this distinction than to distinguish between the fact that someone has a certain blood type, eye colour, bone density, height, or weight on the one hand, and the fact that the same individual is introvert rather than extrovert, is good at mentalizing but still not very considerate toward others, enjoys classical music and hates jazz, pursues certain activities while avoiding others, and so on, on the other. Quite to the contrary: I find it difficult, verging on the impossible, to think of “sex” and “gender” – at least in the Money/Stoller/Millett/Oakley sense – as somehow “interrelated” or “intertwined”.
Consider a person whose sex involves, among other things, that person’s possession at birth of a penis rather than a clitoris. Or perhaps that person’s genital tubercle has developed in a way that is difficult to classify in such binary terms. Or again, the person may have been born without a penis but acquired one later in life (through, e.g., phalloplasty). Whatever the case, I don’t see what it would mean to think of this attribute of the person as somehow profoundly “intertwined” or “interrelated” with that person’s presentation with stereotypically “masculine” or “feminine” temperamental traits and behavioural repertoires (i.e., the person’s gender), least of all how such an interrelation could be observed in the brain. The only sense in which these two sets of attributes could be interrelated or intertwined is the statistical one of correlation, i.e., in the sense that, among those people who present with stereotypically “masculine” temperamental traits and behavioural styles, there is – if indeed this is the case – a greater number of individuals registered as “male” on their birth certificate than of people registered as “female” on their birth certificates. But in that case we’re no longer dealing with individuals (or their brains), but rather with populations.
A different matter altogether is the question of how the two sets of a person’s attributes referred to respectively as “sex” and “gender” develop. This question is but a particular instance of the much more general question about development, which can be schematized as follows: For a given trait X, what are the kinds of input to the process through which an individual comes to develop X? How do those inputs interact throughout this process? How much of the development of X does each individual developmental input account for? Typically, whenever such questions are asked, it is assumed – not unproblematically, but that is the topic of another blog post – that there are two major kinds of input to the process through which a given trait develops, namely, genetic factors and environmental factors, respectively. Because the genetic factors are thought of as “innate” or “inherited” from one’s parents, while the environmental factors are thought of in analogy with the sunlight, air, water and soil nutrients needed for a plant to grow, those two sets of developmental factors are colloquially referred to – again, far from unproblematically – as “nature” and “nurture”. Whence the tired old convention of referring to the question of how a given trait develops in an individual as “the nature vs. nurture issue”.
In the abovementioned proposal that we refer to similarities and differences of brain structure and function between men and women as “sex/gender related similarities and differences”, it seems to me that the original understanding of “gender” as referring to a (set of) psychological attribute(s) of a person has dropped out of the picture. Instead, “gender” now seems to refer to the environmental factors causing men and women to develop stereotypically masculine and feminine profiles in their cognition, temperamental traits and behaviours. Conversely, “sex” now seems to refer to the genetic factors causing men and women to develop stereotypically masculine and feminine profiles in their cognition, temperamental traits and behaviours. By gluing the two together with a slash as “sex/gender”, the idea is conveyed that, for a given trait – where such a trait may be a brain trait – on which men and women may differ or be alike, it is impossible to disentangle the influence from genetic and environmental factors, respectively, on that particular developmental outcome. In other words, the very characterization of the trait differential to be investigated already has loaded into it a theory of how that trait emerges in development. Indeed, it seems the trait differential is defined in terms of the very theory supposed to best explain how the trait emerges developmentally.
I now see two difficulties with this picture, both of which have made me revert to a version of the original Money/Stoller/Millett/Oakley understanding of the sex/gender distinction. The first difficulty is that theoretical questions on which it is only possible (if ever) to pass judgment after reviewing a body of empirical facts – such as, e.g., in the discussion section of a scientific paper – is decided upon at the outset, in and through the way in which one construes the variables to be investigated. This could be important, as the amount and nature of influence from different developmental factors on a developmental outcome may – in principle, at least – vary from trait to trait. If we restrict ourselves only to properties of the brain (being the sole focus of the proposed terminology of “sex/gender” differences and similarities), I would assume there are some brain regions, structures and functions that develop under relatively strong “genetic control” (i.e., that vary relatively little with variations in environmental input), while others – particularly cortical regions, structures and functions – would presumably be much more reflective of the specific kind of environmentally contingent experiences one has during various developmental stages. Here it seems to me that the theoretical question can only be decided on a case by case-basis.
The second difficulty is that no single branch of research – least of all, individual studies conducted within the methodological framework of a single branch of research – is able on its own to decide on theoretical questions regarding how a particular trait develops. This holds no less of brain research than of other branches. A particular finding of a difference between two study populations (e.g., men and women) on a given brain trait of interest – e.g., size of a certain brain region, cross-regional connectivity, patterns of neuronal activation during performance of a particular task or exposure to a particular stimulus – contains little if any information on how this difference has come about in development. Pushing a specific “born that way”, “it’s all down to environmental factors”, or “nature and nurture interact in the most inscrutably complex ways” story requires controlling for so many variables that this is normally outside the field of competence of individual researchers or individual research teams within individual branches of research.
What this all comes to
For these reasons, I now find it best in my own work to go the way of the early pioneers of the sex/gender distinction. This means that, whenever I refer to “sex differences” with respect to some phenotypic trait of interest (e.g., brain structure or function, cognitive ability, temperament, behaviour etc.), I mean simply “differences between males and females”. In so doing, one need not – and I do not – imply anything whatsoever theoretically with respect to which factors exert the strongest influence during individuals’ development of the trait reported to show a sex difference. It simply means a difference, with respect to a given trait of interest, between two specific populations, namely, the population standardly referred to as “males” on the one hand and the one standardly referred to as “females” on the other hand, whether for purposes of research, clinical measures, shortlisting or other affirmative action policies, or what have you. In such contexts, the criteria for inclusion in one or the other population may vary depending on the nature and purpose of the research, measure or policy in question.
Currently, it is not standard procedure to include, e.g., trans men among the study population referred to as “males” in biomedical, neuroscientific and psychological studies looking at sex differences in various traits of interest, but this could change. It is also conceivable – although not overwhelmingly likely – that the bioscientific community at large will, in the course of time, dispense with the idea that mammals (including humans) are sex-dimorphic and begin reckoning with more or other mammalian sexes than “male” and “female”, or quite to the contrary consider the possibility that, at bottom, “everyone is female”; it may even stop reckoning with sex categories altogether.
What, then, about “gender”? In order to avoid confusing the issue of the developmental aetiology of traits with the issue of the nature of the traits themselves, I suggest we avoid speaking of “gender” generically (as in “gender differences”) and instead tailor our gender-talk to the specific issues we’re addressing. Along these lines, I propose to distinguish broadly between gender identity on the one hand and gender norms on the other.
Within gender identity, I propose distinguishing further between an individual’s sense of belonging to one or the other sex(as Stoller had done) and that individual’s sense of how this belonging is most comfortably expressed. Both aspects of gender identity are of an eminently psychological order, conceptually distinct from the individual’s physical characteristics – although, of course, questions remain (unless one is a mind/body substance dualist) as to how such psychological traits are underpinned structurally and functionally in the brain and possibly in the body beyond the brain. The latter would, at any rate, account for the current surge of research interest in brain differences between trans people and non-trans people. But again, whether one looks at gender identity from the side of an individual’s self-reporting or from the side of brain traces, one looks at a developmental outcome the aetiology of which one doesn’t know much in the absence of multiple supplementary sources of data about individuals and populations.
Then there are gender norms, which – being norms – work to regulate, in various domains, the lives of people differentially on the basis of the sex they’re socially recognized as instantiating. As such, they are entertained and enforced by particular social collectives, and either observed or disobeyed by individuals within those collectives. They are not traits of individuals, but rather environmental factors influencing in sex-differential fashion the development of individuals with respect to a number of traits, including cognitive abilities, temperament, self-expression, sexuality, relational styles, activities pursued and avoided, career and educational aspirations, and so on. It was this Stoller spoke to when he wrote of how gender is learned through a “cultural process springing from one’s society”, funneled first through one’s mother’s “idiosyncratic version of society’s attitudes”, later those of other parents, siblings, and friends, until finally “the whole of society present[s] upon [one’s] developing identity”. It was equally gender in my sense of “gender norms” Kate Millett was referring to in the claim that “[e]very moment of the child’s life is a clue to how he or she must think and behave to attain or satisfy the demands which gender places upon one”.
Within gender norms one may further distinguish between gender ideology and gender politics. Gender ideology comprises the ideas, prominent in a given society or culture, regarding what kinds of cognitive abilities, temperamental dispositions, mannerisms, dress-code, activities, interests, occupations, public or political offices and so on come “naturally” with – or are “appropriate” to – being male and female, respectively. It is thus what supplies the content of whatever gender norms are operative in a given society. Gender ideology is eminently expressed through the ways men and women, boys and girls, are portrayed in various modes of mass medial representations, film and literature, as well as within certain genres of scientific discourse.
Gender politics, on the other hand, is the “law enforcement branch” of gender norms. It comprises various institutional arrangements that encourage certain sex-tailored life trajectories and raise obstacles against deviation from such trajectories. Gender politics is also made up all the big or small acts (both public and private) that nudge people – such as by patterns of reward, punishment or over-permissiveness – in the direction of conformity to the gender norms entertained by a given society. For instance: asking, in the course of a broadcast interview, a high-achieving female politician or university professor at reproductive age how she negotiates between her professional or public roles and her role as a parent, while failing to ask the same question of her male counterparts, is a gender-political act as good as any.
To conclude, then: Contrary to a currently influential view, I hold that it is possible and meaningful – both in theory and in practice – to distinguish between sex and gender. This supposes, first, that one distinguishes between the conceptual problematic of defining “sex” and “gender” on the one hand and the theoretical problematic of how traits showing a difference between males and females result from the combined workings of different developmental factors, traditionally – yet most problematically – understood as the nature/nurture issue. Second, it supposes that one rests content with as lean a conception of “sex” as possible (such as, e.g., “whatever criteria are typically used for sorting study populations into ‘male’ and ‘female’ in the context of a scientific study or a clinical trial”), combined with as richly differentiated conception of “gender” as possible (such as, e.g., between “gender identity” and “gender norms”, with further associated subdivisions).
 According to the intersex advocacy group Advocates for Intersex Youth (InterACT), “[I]ntersex is an umbrella term for differences in sex traits or reproductive anatomy” (cf. https://interactadvocates.org).
 John Money, John Hampson and Joan Hampson, quoted in Charlene L. Muehlenhard Zoe D. Peterson (2011) “Distinguishing Between Sex and Gender: History, Current Conceptualizations, and Implications”. Sex Roles (64), p. 792.
 Robert Stoller, Sex and Gender: On the Development of Masculinity and Femininity (London: Routledge, 1968), p. 9. All quotations from Sex and Gender in this and the following paragraph are from pp. 9-10.
 Stoller, Sex and Gender, pp. 41-42.
 Ibid., p. xi.
 Ibid, p. vii.
 Ibid., pp. 65-66.
 Ibid., p. 23.
 Kate Millett, Sexual Politics (New York: Columbia University Press,  2016), p. 26.
 Ibid., p. 29.
 Cf. Ibid., pp. 29-31.
 Ibid., p. 31.
 Ann Oakley, Sex, Gender and Society (London: Routledge,  2015), p. 115. All further quotations from this work in the present paragraph and the two next are from the same page.
 Ibid., p. 135.
 Judith Butler, Gender Trouble: Feminism and the Subversion of Identity, 10th anniversary edition (London: Routledge), pp. 10-11.
 Anelis Kaiser et al., “On sex/gender related similarities and differences fMRI language research”, Brain Research Review 61, p. 49.
 Robyn Bluhm, Anne Jaap Jacobson and Heidi Lene Maibom, “Introduction”, in Robyn Bluhm, Anne Jaap Jacobson and Heidi Lene Maibom (eds.), Neurofeminism: Issues at the Itersections of Feminist Theory and Cognitive Science (Basingstoke: Palgrave MacMillan, 2012), p. 4.
 Rebecca M. Jordan-Young and Raffaella I. Rumiati, “Hardwired for Sexism? Approaches to Sex/Gender in Neuroscience”, in Bluhm, Jacobson and Maibom (eds.), Neurofeminism, p. 106.
 Gina Rippon, The Gendered Brain: The New Neuroscience that Shatters the Myth of the Female Brain (London: The Bodley Head, 2019), p. xxi.
 Melissa Hines, Brain Gender (Oxford: Oxford University Press, 2004), p. 4.
 Cf. Andrea Long Chu, Females (London: Verso, 2019), p. 1. Chu defines “female” as “any psychic operation in which the self is sacrificed to make room for the desires of another. These desires may be real or imagined, concentrated or diffuse – a boyfriend’s sexual needs, a set of cultural expectations, a literal pregnancy – but in all cases, the self is hollowed out, made into an incubator for an alien force” (Females, p. 11).
 Stoller, Sex and Gender, p. xi.
 Millett, Sexual Politics, p. 31.
 I have borrowed this idea from Kate Manne, who in Down Girl: The Logic of Misogyny (New York: Oxford University Press, 2018) distinguishes “misogyny” from “sexism”, proposing to “tak[e] sexism to be the branch of patriarchal ideology that justifies and rationalizes a patriarchal social order, and misogyny as the system that polices and enforces its governing norms and expectations” (p. 20).