Sex refers to the biological differences between male and female, gender to the way in which cultures utilize these differences to construct masculine and feminine people. In other words, sex is given by nature, gender arises from nurture. Differentiating the biological "given" from the cultural "construction" helps us to realize that there is nothing god-given and immutable about gender roles: they could be challenged and changed, and, I would argue, very often should be. From an anthropological perspective, distinguishing sex from gender allows recognition of the fact that norms of masculine and feminine behaviour differ substantially across cultures and through history.
Unfortunately, sex and gender are often used interchangeably, and thus wrongly. Some people mistakenly substitute the term "gender" for "sex" in an attempt to be "politically correct" (oh hateful term!). For example, I read a study entitled "Gender Differences in Pain". The paper was concerned exclusively with the ways that men's and women's biology affects how they experience pain. The authors said nothing about the the social, cultural, or environmental influences on men's and women's experiences of pain, nor did they mention the well-known fact that physicians tend to assume that women, unlike men, overestimate and inflate their pain symptoms. If the paper had done any or all of that, it might indeed have been a study of gender differences in pain; as it was, it was actually a study of sex differences in pain. Using the more "correct" term gender added nothing, and was just plain wrong.
It is common in western cultures to construct concepts into dichotomies, and my first paragraph was rife with them:
- sex vs. gender
- male vs. female
- masculine vs. feminine
- man vs. woman
Interestingly, however, when you probe these terms more deeply, things begin to fall apart. It's wrong to take these oppositions at face value, for there is substantial evidence that these apparently opposed categories are in fact misapprehensions.
Let's start with sex. Even on the surface, sex distinctions are not always clearcut: many individuals are born with ambiguous genitalia (hermaphrodites). In "simpler" cultures where bodies have traditionally been bared for all to see and privacy was unknown, such people must have been known and accepted for what they were. In the western past the "inter-sexed" could perhaps have kept their secrets hidden under layers of dusty flea-ridden cloth for only their nearest and dearest to know. Today in the west the ambiguously genitalled are commonly "fixed" through surgery, often soon after birth.
But really, biological sex is about much more than just genitalia. There's a genetic component to it - you know, those X and Y chromosomes - and there's a hormonal aspect to it as well. (Which is why hormones are given to kids at puberty if it's revealed that that long-ago decision in the face of a micropenis or false vagina - should we make it a boy or a girl? - was the wrong one.)
In spite of these ambiguities, in human society people are assigned a sex, and that's a pretty significant assignation, for onto the foundation of (presumed or apparent) sex is erected the edifice of gender. Children learn from a very young age to recognize their culture's norms of masculine and feminine comportment. They're pretty clear on how men and women are supposed to behave, even if they see all the time that in real life these norms are regularly broken: mommy fixes the leaky tap so it really stops dripping, daddy makes much better cake. Western people, steeped in the tradition of discrete categories, paper over these anomalies for the sake of avoiding extreme cognitive dissonance, but we experience them all the time.
Even more confounding of a dichotomous gender system are those on the fringes of gender norms - queers, they have begun to call themselves in the west, carving out their own linguistic space - the butch woman, the effeminate man, the androgyne whose "real" gender you just can't pin down once and for all. They embody the shakiness and unreality of the masculine/feminine paradigm in a wonderfully refreshing way.
Modern surgical techniques allow the transgendered to physically mold their bodies in order to align their genitalia with their gender identity. But that's a very recent phenomenon. In our past, as in many non-western cultures, there are well-established traditions of naming and accepting individuals whose gender does not conform to their sexed body. Berdache in First Nations cultures, kathoey in Thai are just two of the many examples I'm aware of. So queers can perhaps be seen as reclaiming that space that was lost when gender got so rigidly riveted onto sex.
And then there's sexuality. For onto these shaky constructions of sex and gender, which seemed so black and white at first, but ended up to be grey gray grey, was placed the sexual dichotomy: heterosexual vs. homosexual. But sexuality is another notoriously shady continuum, with at the very least bisexuality straddling the poles. And there's undoubtedly a whole lot more flexibility to sexual expression than those simple het/homo containers can hold. Foucault famously said that the homosexual didn't exist in Europe before the 18th century, and intimated that men found pleasure together without ever questioning their identity. For that's what he really meant: there was no homosexual identity, no definition of a homosexual, and therefore the acts that we would today call homosexual were simple bucolic pleasures, nothing more.
The whole nexus of sexuality can be constructed in other ways too. In many cultures, men's sexuality is defined by their role in "the act": if you penetrate, you're masculine, a "real man"; if you are penetrated, you're a homo, a lady boy, a femme. (Lesbianism, of course, is completely invisible in these systems, because there's no penetration taking place, or at least none with a penis.) And who could forget the infamous Greeks with their boy-loving men? Christians shudder now, but at the time it was just fine and dandy, and no one was labelled a deviant there; it was a male sexual hierarchy of age.
And here I've arrived, perhaps, at the crux of the matter. For sex, and gender, and sexuality, are aspects of complex systems of power which have been labelled sex/gender systems. I was being a bit disingenuous suggesting that the dichotomies I've been speaking about arose from our penchant in western cultures to think in oppositional and mutually exclusive pairs. That's true, but such polarizations serve another purpose: they feed, and support, the webs of power which run through our social fabric. They define who's normative and who's a freak, who's acceptable and who should be shunned. Thus power coalesces particularly around the bodies and actions of older, richer men, but also around all who fall on the "right" side of a norm, while resistance is incited in those on the other.