Sex and Gender 101 (WIP)

[fenrischained]

CONTENTS
i. Disclaimers
ii. Introduction
    1. What is sex?
    2. What is gender?
iii. Sex
    1. Chromosomal sex
          a. Chromosomal development and impact
          b. Chromosomal variation
          c. Connection to anatomical and hormonal development
    2. Hormonal sex
          a. Primary sex hormones and their functions
          b. Hormonal balance variations
          c. Puberty
    3. Anatomical sex
          a. Primary sexual characteristics
          b. Secondary sexual characteristics
          c. Trends in build and height, etc.
    4. Reproductive capacity
          a. Overview of reproductive sex differences
          b. Fertility and infertility
          c. The menopause
    5. Neurological sex
          a. Neurological differences between men and women
          b. Physiological or psychological? Assessing the impact of social pressures on brain dimorphism.
iv. Gender
    1. Self-identification
    2. Social factors
           a. Gender presentation
           b. Gender roles and expectations
           c. Cultural variation in gender expression
    3. A spectrum or a cloud?
v. Conclusion - the importance of changing our model
vi. Further reading
    1. Recommended articles
    2. Citations

i. Disclaimers
This is probably going to take quite a lot of time, between writing and citing, which is part of why I'm posting it here rather than to Tumblr because who even still checks LJ?

I wanted to pull together a resource for discussions of sex and gender, mostly from a scientific perspective, in light of the number of timse I've been told "no, sex/gender is simple" by people who base their science on secondary school biology. I'm not an expert on all these factors (I'm an anatomist and physiologist, not a psychologist or geneticist) but in all cases I'm going to try to use citations to back myself up. I'm also going to focus exclusively on human sex and gender, because while there are important and cool things to be learnt from other animals, I'm a medical scientist rather than a zoologist and this post is going to be long as hell already.

Also, I'm trying very hard to be as impartial as I can, but obviously I have an opinion and it may come through. If you have evidence against anything I say here, I would genuinely like to see it, and hopefully adjust accordingly.

With that said, let's dive in.---
ii. Introduction

What Is Sex?

Obviously, we're talking about the concept, not the activity. That's a whole 'nother ballpark.

A lot of people say "gender is psychological, sex is physical/biological". As a basic model, that mostly works. The trouble is, like most of biology, it's more complicated than that. When you start taking a look at human biology (or... actually, most animals) it turns out that "sexual dimorphism" (physical differences between the sexes) is actually way more complicated than it looks.

Sex in humans can be roughly divided into 6 axes:

1. Chromosomal sex. The distribution of chromosomal pair 23, typically (but not always, as we'll see) XX or XY in humans.
2. Hormonal sex. The balance of "male" sex hormones (testosterone, primarily) and "female" hormones (oestrogens, progesterones, prolactin, endorphins, etc.). It's important to note that everyone produces both male and female hormones: the difference is in their ratio.
3. Primary anatomical sex. Sex characteristics which are considered "primary" are those both tightly linked to sex and present at birth - genital configuration, pelvic layout, and abdominal layout.
4. Secondary anatomical sex. Sex characteristics which either develop at puberty or later (e.g., breasts, pubic hair, facial hair), or which are more loosely linked to sex categories (e.g., height, fat distribution, skeletal anatomy).
5. Neurological sex. This is... really a subset of category 4, but I'm giving its own classification because while differences between male and female brains (structurally and physiologically) have been observed in multiple studies, what causes this difference is very unclear, and research hasn't really confirmed how much is "biological" (by which I mean a predictable outcome based on genes and embryonic development) and how much is social or psychological differences in upbringing. And that's a really interesting discussion, honestly, so it gets its own category.
6. Reproductive capacity. Arguably a component of sex, since sexual dimorphism is pretty much just there for reproductive purposes.

It's actually a little more complicated - other factors may also be involved. But these 6 categories cover most of human sexual dimorphism.

The reason this is important is that these five axes do not necessarily match. A person who is chromosomally female may have male hormonal and anatomical traits, for example. We'll discuss the interconnectedness and semi-independence of the factors of sex at the end of the post, with examples.

What is Gender?

This one's harder for me to address, and I'm going to largely skim over it, because other people have written much better about it than I can. Frankly, gender confuses the fuck out of me. But as far as I can tell, what we talk about as gender also consists of separate axes:

1. Self-identification. Arguably the most important: what do you think your gender is? This may be the be-all and end-all of gender, or it may not; I'm not here to argue that point. But there definitely are other aspects to what people mean in discussion of gender.
2. Social classification. What gender society treats you as. This includes what gender you look like, what gender you're assumed to be, and what gender is on your official paperwork. Important in discussions of gender, especially in understanding how both trans men and trans women typically have experience of misogyny.
3. Gender roles/presentation. Closely linked to social classification; the degree to which you conform to your culture's concept of gender, in terms of everything from clothes to speech patterns to lifestyle and aspirations. I'm separating this from social classification here because gender presentation is about the individual, rather than the response they get from their environment.
4. Neurological sex. Maybe? Again, it's unclear how much of the biological difference in human brains is intrinsic and biological (which I would classify as sex) and how much is cultural and psychological (which I would classify as gender).

v. Why Do I Care?

I don't mean me specifically. (I care because I'm a nerd and people misapplying biology irritates me). But what impact does this have on how we discuss sex and gender? WARNING: THIS IS THE EQUIVALENT OF AN EDITORIAL, IT'S OPINION RATHER THAN SCIENCE.

Well, first, it's important to understand that neither sex nor gender is entirely binary. It's vital to understand that, while there exist women who match perfectly to our expectations of female sex and men who match perfectly to our expectations of male sex, they are a tiny minority, even within cis populations. Most women have some biologically "male" traits, and vice versa.

It helps me to think of sex as a statistical construct - like race or BMI. The categories are useful on a large scale. It's often meaningful to say, for instance, "women are more likely to develop breast cancer, men are more likely to develop bowel cancer". And this helps us structure things accordingly - on a medical level, for example, we're likely to screen people we've identified as female more closely for breast abnormalities, and male patients more closely for bowel obstruction.

The problem comes when we use sex as an individual construct: you are a woman, thus you have these traits. To extend the analogy, that would mean every woman has breast cancer and everyone with breast cancer is a woman - both blatantly untrue.

Sex is mostly important when looking at things from a statistical perspective, even in medicine. We should not assume a diagnosis or a trait based on another, semi-unrelated trait, especially when we don't understand the causal link fully. If an apparently cis woman presents with a genetic complaint associated with male chromosome configuration, we have to at least consider the possibility that she may be genetically male. At the same time, we also have to treat her as female in terms of anatomy and hormonal balance - she will have some tendencies towards diseases associated with men, where the link is genetic, but where the link is physiological she's more likely to be at risk of diseases predominantly affecting women.

It's also important to recognise that "intersex" is a much broader category than many people think, and may be undiagnosed (most people don't know for sure what their chromosome 23 configuration is, since we don't routinely karyotype people unless we have a clinical reason), and may also have no discernable effect. Understanding this may help us to destigmatise intersexuality, both socially and scientifically.

Mostly, though, I just want us to take a step back and realise that "biological sex" is not simple. It is not binary. (Honestly, nothing in biology is simple and binary, the world is a confusing mess and likes to fuck with scientists). And that has immense impact on how we talk about sex, but also how we talk about transness and cisness. We have to recognise - whatever side of the argument we're on, and while I'm not going to pretend I don't have a side, I've seen this crap from trans allies and gender abolitionists as well as conservatives and radfems - that you cannot meaningfully talk about biological sex without acknowledging that it's complicated, multifactorial, and not necessarily obvious. We need to move away from the idea that biological sex is the simple and predictable side of the sex/gender equation, because it's just as complicated and, frankly, just as arbitrary as gender.

Sex is not a simple biological mandate. We made it up. That doesn't mean it's not biologically relevant, that it doesn't exist, or that it isn't scientific. The entire nature of science is to classify things, and we classified sex pretty broadly but still meaningfully. But we have a tendency to act, when evidence appears that conflicts with our model, as if it must be the evidence that's wrong.

And by the way, I'm not actually suggesting we should stop recognising male and female sex as biological classifications. It's a limited model, but it's an extremely useful one, and there are a whole lot of fields in medical science where it's crucial. Again, I'm an anatomist: I recognise the value of being able to have a sense of "if they're male their anatomy is probably this, if they're female it's probably this". But the key word there is probably. We can't set aside sex as a concept, it has vital importance to medicine and human biology. I just think we need to assess our model critically, recognise that it is a model, and keep an eye on that "probably".