"How many genders or sexes are there?" Jaak Panksepp asks his students.
Panksepp, who is the father of affective neuroscience and currently Baily Endowed Chair of Animal Well-Being Science at Washington State University, waits patiently for them to overcome their confusion and venture the obvious answer: "Two."
"No, there are at least four, and probably many more," he informs them. The standard setup is, of course, a male brain in a male body or a female brain in a female body, but we regularly find a brain-body mismatch; feminized brains in masculinized bodies and vice versa.
When I was an undergraduate, studying the humanities, we were taught that being gay was not a biological phenomenon, nor was gender, for that matter. Professors of the humanities and social sciences saw all biological explanations of human behavior as reductionistic and deterministic. If anyone tried to suggest brain-based or neurochemical avenues of explanation, a detour would be erected to take the students into the terrain of psychoanalysis, or social constructionism, or if the professor became too frustrated he would just remind students of social Darwinism, eugenics, and finally stop all such explorations by mentioning Hitler.
Now that I'm a professor, I'm saddened to find that not much has changed in the attitudes of my humanities colleagues—many of whom still vilify biological explanations of human behavior and culture. The Harvard professor of English Louis Menand, for example, a Pulitzer Prize winner, warned humanities departments, in his 2004 MLA talk "Dangers Within and Without," to stay away from biology. But while not much has changed in the humanities and social sciences, a lot has changed in biology. While humanists weren't looking, biology (genetics, embryology, evolution, neuroscience, etc.) left behind many of its deterministic pretensions and embraced the indeterministic developmental logic of epigenetics—the complex interface of nurture and nature. Biology now recognizes the immense domain of external triggers and influences (from intrauterine environment to social structures) that shape phenotypic expression of genetic possibilities. Biology has become dialectical.
How did the humanities and social sciences miss this exciting transformation? In the 1970s and 80s, feminists drew an important distinction and created a new language for fruitful discussion. The distinction drew a line between sex and gender. Sex referred to the reproductive categories of male and female, and it was a useful biological concept, applicable to humans, nonhuman animals, and plants. Gender, on the other hand, indicates the socially constructed roles, behaviors, and traits of male and female. Gender categories may correspond to sex categories, but they need not. This useful distinction, and subsequent academic conversation, were fuller realizations of Simone de Beauvoir's famous 1949 statement, in The Second Sex, that "one is not born a woman, one becomes one." This existential rejection of essentialism sought to break the oppressive tendencies of anybody who used the "nature of woman" as an excuse for mistreatment.
An academic division of labor resulted from this distinction. Sex remained a productive topic (excuse the pun) for biologists, who are interested in the genetic, developmental, and chemical pathways of male/female dimorphism. People in the social sciences and humanities, by contrast, made gender, not sex, the subject of their work. In gender studies, we learn about the ways that men and women "perform" their respective roles—people of male sex can perform as female gender, and vice versa, by adopting modes of speech, dress, behavior, and even values. There is no talk of innate instincts or brain differences in gender studies.
In the 1980s and 90s, psychoanalysis was used to connect gender to early developmental dynamics in the family. Evelyn Fox Keller, for example, argued that men are more detached, objective, and stereotypically scientific, because their identity formation has to detach twice from the mother, while women have to detach only once. We all separate ourselves from mother and thereby attain an ego—a self. But as a boy, I must also detach again, in an unconscious realization that I am not even the same kind of thing as my mother (i.e., I've got this thing between my legs, etc.). Male identity, in this view, is alienated twice from the mother, producing human beings who are more remote, more distant. That is just an example of the sort of dominant, nonbiological explanation of difference that flourished in gender studies.
In addition to these theoretical approaches to gender, much of gender studies focused on the many ways that prejudice informs gender positions and relations. Gender is a politically and socially coerced category, and patriarchy is considered to be an ever-looming threat. Subsequently, issues of power are at the forefront of gender studies, and many theorists have applied the Marxist class-struggle lens to gender issues, substituting men for the bourgeoisie. Contemporary cultural studies, for example, has given itself over almost completely to that approach.
In this division of labor between nature and nurture, psychology found itself in a middle position. The life of the mind is sometimes considered the most autonomous domain, free of deterministic physical forces. According to this view, evolution stops at the neck. But, on the other hand, brain science and genetics in the 1990s and 2000s began giving us some impressive evidence that higher-level thinking and behavior are products of biological causation.
Unfortunately the loudest of the new biological psychologists were the most extreme—the wildly popular evolutionary psychologists (e.g., Steven Pinker, John Tooby, and Leda Cosmides) who added a hyperadaptationist ingredient to their reductionism and tried to usurp every aspect of the humanities and social sciences. For those scientists, most everything about us, including gender, is biologically determined. The evolutionary psychologists were, and are, everything the humanists and social scientists feared. Never mind that they weren't real biologists and worked with a cartoon version of Darwinism—they still got giant grants, wrote best-selling books, and became go-to authorities for many media outlets.
During the same period, many feminists and social scientists (e.g., Elisabeth Lloyd, Sandra Harding, and Donna Haraway) started striking back at this sort of reductionism, but rather than hold the line on the sex/gender distinction (a line that was wise and prudent, in my view), they sought to go further and deconstruct the sciences themselves. Over the past two decades, they have tried to bring biology itself into the odious lineup of "suspects" accused of being abusive "power discourses." These more recent foes of biology have tried to cast aspersions on science, arguing that it's just as constructed as any social reality (often forgetting the distinction between the logic of discovery and the logic of justification). From their own side, these deconstructionists have pursued an isolationist approach, arguing that nothing is innate—that gender, race, sex, and nature itself are just realities constructed by those in power.
The French philosopher Michel Foucault set the agenda when he lamented, as early as 1976, that "the notion of sex made it possible to group together, in an artificial unity, anatomical elements, biological functions, conducts, sensations, and pleasures, and it enabled one to make use of this fictitious unity as a causal principle." Following this approach, more-recent theorists like Anne Fausto-Sterling and Judith Butler have argued that even the biological categories of sex are just artificial inventions, designed to keep women and intersexed peoples down. Society, they suggest, decides which of us are males and which are females—pushing everyone into rigid binary categories.
There are two main arguments that are usually offered in defense of this controversial thesis that sexual dimorphism is political rather than ontological. One is based on a general critique of knowledge (an epistemological argument), and the other on a specific picture of reality (a metaphysical argument). I will offer counterarguments to both.
First, let's look at the epistemological idea, stemming from a general skepticism about human knowledge, that sex categories are socially constructed. Butler's view, in her book Gender Trouble (Routledge, 1990), that all identity categorization is inherently hegemonic, is symptomatic of the basic logic. Proponents of that notion argue that since all knowledge comes through the senses, and sensory data are always mediated by our perceptual equipment and our political agendas, then we can't have direct access to reality. Add to this the now classic postmodern view of language—that words or signs are never fastened to their referent but hang suspended in the eternal fog of différance (i.e., Jacques Derrida's always deferred meaning). Now complete the skeptical picture with some loose talk of Thomas Kuhn's paradigms (conceptual frames that shape and filter our knowledge), and the foes of biology have all the putative ingredients for a complete skepticism about scientific objectivity. Applied to sex categories, this means that we can't know what constitutes a real man and a real woman (beneath their appearances, morphology, behavior, etc.) because we can't have knowledge of any objective reality. I submit that this is an unwarranted and melodramatic position.
Like the social constructionists, many of us critical realists accept the fact that knowledge is mediated. Everyone has known this since Immanuel Kant showed how all experience is shaped in part by our mental and perceptual faculties. The 20th century rightly added the influence of language to this list of mediating influences. But the fact that experience is open to different interpretations does not eliminate objectivity, and the fact that science is fallible and lacks certainty does not render it just another political power discourse. Yes, even so-called facts have some mediated aspects (e.g., mathematical symbols or values like parsimony—science prefers Occam's-razor simplicity when it comes to metaphysical assumptions). But while a theory, for example, of blood circulation might employ metaphors and models, it's not the same as a political ideology or a performative creation. Rather, it's a corroborated causal theory that tells us how the body works, independent of any politics.
Science has always functioned just fine without certainty. The expectation that science should be an indubitable mirror of nature—and that it has failed to live up to that expectation—betrays a naïve view of science (most recently held by our constructivist friends). We may not have a God's-eye perspective on nature, but that does not mean we are blind. The mediation of our knowledge may prevent perfect reflections of nature's exact contours, but nature does come to us in discrete forms. Sex is one of those discrete forms (a natural kind), and only radical skepticism suggests that we must arbitrarily impose sex categories because we can't be certain about our perceptions of males and females.
The metaphysical argument brought by the foes of biology is different, but also based on skepticism of traditional categories. It has become standard dogma in gender studies to cite Anne Fausto-Sterling's statistics about intersexed people. An intersexed person is one who displays intermediary or atypical combinations of male and female anatomy. Ambiguous genitalia, for example, can make it difficult for doctors to determine a sexual category for a newborn, and frequently a sexual-assignment surgery will be done to "clarify" the sexual identity (constructing a more definitive vagina or penis, for example). Intersexuality describes a person whose sexual genotype (actually chromosomal makeup) or phenotype (genitalia) is neither exclusively male nor exclusively female. It is rare to find both testicular and ovarian tissue in one individual. But more commonly, a person will have a male chromosomal pattern XY but then have hormonal abnormalities in utero (e.g., adrenal-gland problems), causing the growth of external female genitalia. And vice versa: XX females will get abnormal doses of virilizing hormones in utero and develop a mock penis.
The existence of intersexed people has been well known throughout human history; they have enjoyed elevated social status in some societies but more often been persecuted (e.g., early Roman law required them to be drowned upon discovery). But in all previous times, it had been assumed that such exceptions, such intermediary sexes, were rare. They were exceptions. They were atypical.
More recently, however, Fausto-Sterling has argued that such intersexed people are much more widespread in the population than previously believed. She has led a new wave of social constructionists to argue that the male/female sexual binary is really just a shaded continuum—the poles of which represent traditional masculine and feminine physical equipment, while the vast middle ground is all manner of biological ambiguity. If that is true, it lends credence to the idea that even biological sexual identity is by convention. We are all biological intermediaries, and there are no fixed kinds. The metaphysical assertion is: Nature comes to us like undifferentiated cookie dough, but we apply science (and, of course, prejudice), as the cookie cutters, to create discrete categories of male and female.
Is sexual dimorphism just an artificial imposition on a metaphysical continuity? Fausto-Sterling originally put the figures of intersexuality very high: almost 12 million in the United States (4 percent of all births), while Leonard Sax, with the Montgomery Center for Research in Child and Adolescent Development, puts the figure at around 50,000. Sax argues that Fausto-Sterling has inflated the numbers by including groups who are not truly intersexual. A high number would help validate Fausto-Sterling's belief that gender is a "social construction" rather than a biological fact. But the scholar Carrie Hull has definitively shown that Fausto-Sterling's numbers are indeed inflated. In her book The Ontology of Sex (Routledge, 2006), Hull points out that Fausto-Sterling subsequently revised her numbers down, from 4 percent to 1.728 percent. When Hull checked the math of the new figure, however, she found significant error, and (using Fausto-Sterling's own data) placed the proportion at a mere 0.373 percent. That clarification suggests that intermediaries are indeed very rare, and that the traditional categories of male and female are accurate pictures of nature.
Science does, however, give us some fascinating insight into genuine sexual ambiguity. In addition to the very real intersexed bodies (albeit a smaller population than we thought), there is the much more prevalent brain/body mismatch that Panksepp and others have investigated. Mammal brains and bodies, including ours, start out originally as a female template. Then, in utero, testosterone triggers the masculinization of both brains and bodies, via two different chemical sequences. Estrogen, facilitated by the enzyme aromatase, mediates the influence of testosterone on the brain, and dihydrotestosterone (DHT) and the enzyme 5-alpha-reductase do the same for the body. Panksepp, who experiments on rats and other mammals, explains that "both humans and rats can have female-type brains in male-type bodies (if DHT was present in sufficient quantities but estrogen was not) or male-type brains in female-type bodies (where estrogen was present but DHT was not)." Some provisional data suggest that people who get sex-change operations show a structural mismatch between brain and body sexuality.
The masculine brain differs from the feminine brain in several ways. The male brain lacks the hemispheric coordination of the female brain, in large part because the female has greater connectivity of the corpus-callosum fibers. Less well known are important differences in the subcortical areas that activate during sexual behaviors, like the interstitial nuclei of anterior hypothalamus (INAH) or the corresponding preoptic area (POA) in rats. Those areas, which are enlarged from masculinizing hormones during development, are highly activated during male pursuit of females and subsequent copulation. And a recent Swedish study has confirmed that the amygdala of the human homosexual brain more closely resembles that of the opposite sex.
Beyond mere anatomical differences, biological experimentation has also taught us interesting facts about the development of sexual preference in mammals. In repeated and corroborated tests, stress in rat mothers has been shown to produce significantly more male homosexual offspring in her litter. Ordinarily the male portion of a normal litter comprises 80-percent studs, who mature during puberty to engage in male sexual behaviors, and 20 percent that are asexual, displaying neither male nor female sexual behaviors. But if the pregnant mother is put under stress (bright lights, foot-shock, overcrowding), then only 20 percent become studs, 20 percent remain asexual, and 60 percent become either bisexual or exhibit exclusively female sex behaviors. This well-confirmed test indicates that stress can actually suppress brain masculinization. Such tests are not meant to "solve" the causal question of homosexuality, sexual dimorphism, or brain/body mismatch. The causes will be complex, varied, and unique. But such experiments do illustrate the relevance of naturalistic biological influences on sex and even gender categories.
Of course, linking interesting correlations between sex-based brain difference and complex human psychology is a risky move that needs a cautious, sensitive, and enlightened approach. Gender consciousness cannot be reduced to the influences of testosterone on brain and body, but we also can't ignore or write off such influences. Testosterone is necessary but not sufficient for understanding sex and gender difference.
The real reason that some humanities scholars want to throw doubt on science generally and "female nature" specifically results from a long history of prejudiced essentialism. When sex categories are supposed to be fixed, then anyone who does not fit neatly in the boxes is seen as an outcast. That is a lamentable conservative history, but recognizing that nature has definable contours and categories is not inherently conservative. It can easily buttress a liberal, tolerant ideology as well. In fact, Fausto-Sterling's scientifically informed original suggestion, that we should adopt five sexes instead of two, was in keeping with both a liberalizing ethos and scientific findings. Her five sexes were based on genital anatomy. But more-radical rejections of sexual categories by the foes of biology influenced Fausto-Sterling to withdraw from the ontological middle ground and disown her earlier claims of distinct kinds. She was made to feel, apparently, that she hadn't gone far enough with her deconstruction of sex. And, unfortunately, she accepted that criticism.
The solution is not to argue that there is no such thing as "male/female" or "normal/abnormal" or "typical/atypical." Instead of arguing that nothing is normal and we're just making it all up, we should learn how to celebrate diversity and uniqueness for what it is. People who do not fit into traditional gender or sex categories should be able to say, I'm different, and different is great. There are ordinary sex categories, but we should celebrate the extra-ordinary. In that way, we don't have to dismiss reality just to make sure people are treated with respect.
Tolerance is premised not on a denial of reality, but on a better interpretation of the facts. Perhaps we should start to adopt Panksepp's suggestion of four categories or combinations of male/female traits—which are based on brain/body configurations—and merge those with Fausto-Sterling's original genitalia-based five sexes. In any case, we should not follow the foes of biology. We should probably retain the useful distinction of sex and gender, and accept that biology gives us significant access to human nature and even male and female natures—but also that gender studies gives us understanding of the rich diversity inside those malleable natures.
Thankfully, increasing numbers of humanities scholars—ignoring Louis Menand's warning—are slowly getting over biophobia. What's needed, however, is a smart fusion, not just any fusion (see the often dumb reductionism of both evolutionary psychology and literary Darwinism). Academics might follow the clearheaded analysis of Natasha Vargas-Cooper's recent Atlantic article, "Hard Core: The New World of Porn Is Revealing Eternal Truths About Men and Women" (Jan./Feb. 2011). Vargas-Cooper, who calls egalitarianism about sex/gender an "intellectual swindle," may get some things wrong, but at least she is trying to understand the biological roots that feed the cultural fruits.
Evelyn Fox Keller, who spent her earlier career disentangling gender from sex, may now be showing us the way forward by re-entangling them. In her recent book The Mirage of a Space Between Nature and Nurture (Duke University Press, 2010), she emphasizes the plastic relationship between genes and environment, and tries to counteract our tendency to privilege one cause over another by emphasizing "developmental pathways" rather than just bottom-up (molecular) explanations or top-down (structural) explanations. Regarding the sex/gender issue, then, we should be asking, among other things: Which traits are malleable, and to what degree? The answers will come from a prudent marriage of biocultural analysis, because developmental pathways don't recognize academic divisions.