6 Types of Sex

Why are we relying on the 3 least reliable sex markers to determine a person’s legal and social gender?

Early proponent of sex reassignment, John Money, described six types of sex[1]. His aim was to tease out the ways in which one might “trans” or change sex by breaking sex into a number of negotiable components.

Of course we know that sex is immutable, and changing one dimension won’t change your whole sex.

But let’s play along.

  1. Chromosomal Sex – most people are XX (female) or XY (male). Chromosomes permeate every cell and cannot be changed. See notes below variations on disorders of sexual development.
  2. Anatomical or Morphological Sex – Primary and secondary sexual characteristics such as genitals, facial hair, breasts. These can be observed and is usually how babies are sexed at birth. Their vulva or penis is observed and this is taken as a reasonable measure of the sex.
  3. Genital or gonadal sex – testes in a male and ovaries in a female. This cannot be changed.
  4. Legal sex – what it says on your passport, birth certificate, driver’s licence or other documents of identity.
  5. Endocrine or Hormonal Sex – levels of estrogen and testosterone, and their effects on the body. Males tend to higher testosterone and females tend to higher estrogen.
  6. Psychological sex – the state of feeling one is a male or a female.

How reliable are these measures?

Let’s see whether each one is patent (can be easily observed), reliable (is backed up by other measures) and immutable (cannot be changed).

Chromosomal sex cannot be altered, but can only be confirmed with genetic testing. Chromosomes are reliable – an XX is female and an XY is male. There are other chromosomal configurations that make up a small percentage of people. Chromosomal sex is immutable – it cannot be changed.

Anatomical sex (breasts, hair growth, vulva etc) can be easily seen, but isn’t reliable. An XY person who is insensitive to androgens may appear to be female. It is not immutable because hormones and surgery may change the appearance to some extent. Phalloplasty can give you a phallus, but not a penis. Vaginoplasty can create a crevice but not a vagina.

Genital/Gonadal sex can be observed in males who have external testes, is a reliable marker of sex and is immutable. An XY person who appears female will have testes, although these will be internal. It is usually patent, reliable and immutable.

Which markers os sex should we base our legal definitions of male and female upon?

None of Legal, Endocrine or Psychological sex are patent. They cannot be observed by looking at a body. These types of sex are closer to being components of gender.

They are not reliable, bearing no relationship to any of the other measures of sex. A person might feel like non-binary, take male hormones, and have a female passport. YouTuber Luxander fits this bill exactly.

These 3 sexes are not immutable. Legal sex can be changed using a form. Psychological sex can be changed with the weather. Hormonal sex requires a prescription or a developmental event such as menopause. We would not say that menopausal women are really men. Why do we say that males who take estrogen are really women?

Using the sexes as proof

On the one hand, there are the biological and immutable sexes. Their definitions buttress one another – chromosomes drive the formation of primary and secondary sex characteristics. Gonads are primary sex organs, and these produce sex hormones that further develop & differentiate the secondary sex characteristics.

On the other hand are more pliable definitions that tend to follow from one another in a chain.

A psychological feeling of womanhood leads a man to request hormones and then surgery. This commitment is taken as ‘proof’ that he is legally entitled to become a woman. Voila – a new legal identity is created, and rights conferred, predicated on a subjective notion of what it might be to be a woman.

The idea that one can ‘change sex’ is founded on gender not sex.


Is it meaningful to change these superficial markers of sex? What does sex means outside of gender. Or gender outside of sex? Does a change in gender entitle one to claim to have changed sex?

What females have in common with other females is their shared experience of a female body. The body may be clothed in stockings and lace, or in denim overalls. It is a female body that grows breasts, bleeds, produces eggs and possibly children. There is a shared experience of developing and living in these bodies. Even if a female does not to some or all of these things, her body has the potential to. Her experience is physically determined because her sex is physically determined.

A male altering his hormones and giving his body a female appearance cannot achieve female chromosomes and gonads. He might be entitled to claim femininity but not femaleness.

Women-specific rights are based around the shared experience and demands of the female body. Pregnancy, the risk of rape, the drains of menstruation, the trials of ‘the change’, and the rollercoaster of motherhood. The disappointment if you can’t have children but want to; the social pressure if you eschew having children by choice.

Allowing a man to ‘become a woman’ based on his subjective idea of being a woman opens the door to any man to declare that he is entitled to women’s rights and protections, even though he will never need them.

He is still a man. As a man he feels he is entitled.


Read this book. I know it looks a bit scary but it’s well-written and prescient.

[1]: The Transsexual Empire by Janice Raymond, p6. If you haven’t read The Transsexual Empire, click off and go read it now for free.

Gender: either of the two sexes (male and female), especially when considered with reference to social and cultural differences rather than biological ones. The term is also used more broadly to denote a range of identities that do not correspond to established ideas of male and female.”a condition that affects people of both genders” Google Dictionary

There are only so many qualifying ‘air quotes’ that can usefully be added into a paragraph.

Addendum – How reliable are chromosomes anyway?

Updated on 3 January 2020 with notes from Freya.

I’ve stated that the presence of a Y chromosome means male. It isn’t entirely that simple, but the complexity doesn’t undermine the reliability of chromosomes as a measure of sex. The fact that we can detect and study these variances furnishes us with an understanding of how they work.

When you examine chromosomes they indicate a definite sex or an intersex condition. There are a number of disorders of sexual development (intersex) where a person has different chromosomes other than XX or XY, or where a person’s body develops differently. Together these conditions are rare. Taken individually, they are vanishingly rare.

Confronted with abnormal chromosomes, decisions are made.

Take the woman with 46XY chromosomes who went through puberty, menstruated and gave birth to children. Is she female?

Here is where the 6 sexes are useful. Her body appears and functions as a female body. Her hormonal level are in line with the expectation for females and she has functioning gonads. (I’m not actually a doctor so I’m winging it a bit on that statement). Her legal, and presumably psychological sex are female.

In Turner Syndrome – one of the two X chromosomes that are typically present in the cells of females is missing or incomplete. Most affected women will not experience breast development and many will not have menstrual periods.

There are variations related to the SRY gene that typically attaches to the Y chromosome cause a female development in an XY male. But can attach itself to an X and cause masculine development in an XX female.

Confronted with abnormal chromosomes, decisions are made.

The first time I came across “Intersex” was reading that babies with “ambiguous genitalia” were operated on soon after birth to fix them up and they were raised as the chosen gender. The feminist text that reported this did so in an appalled tone. There is now more awareness of intersex conditions and people with disorders of sexual development. Hopefully these practices have reduced.

Still, choices are made. Chromosomes are not examined in a vacuum. It takes effort to find out a person’s chromosomes and you would likely do so only to explain a variation.

Categories, not a spectrum

Opening up a category for XY people with complete androgen insensitivity does not invalidate the validity of the male/female divide. Nor does it make sex a spectrum. A spectrum is continuous; a rainbow is continuous because the wavelength of light can be any number. Human chromosomes cannot be anything at all, they are variations on discrete values.

A new variation in sex is just that – a pocket of people who are different, but no less human.

2 thoughts on “6 Types of Sex

  1. I don’t know about Australia, but here in the UK, a passport is not a reliable indicator of the sex (or ‘legal sex’) of the holder because it can be changed without any legal process, just with a letter from your General Practitioner and filling in a form. This may or may not match what your birth certificate says, but then again, a birth certificate may indicate your ‘legal sex’ (ie your sex for some legal purposes) but it is not a reliable indicator of a person’s sex because it is switched to indicate the sex the holder is not when a Gender Recognition Certificate under the Gender Recognition Act is issued.


    • Thanks for the info Alan. The rules here are created by each state. The Federal government paved the way in 2013, allowing states to require only a doctor’s note as proof of sex on a passport.

      Each state though has a different requirement.
      NSW, QLD – self ID but SRS is required
      SA, WA, ACT, VIC, TAS, NT – self ID

      There’s a handy table on this page – https://en.wikipedia.org/wiki/Transgender_rights_in_Australia

      The language around the law changes for self ID all talk about “dignity, respect and human rights”. The language is of “forced divorce” and “forced surgery”. I find it galling. It’s like saying that the railways “force” you to buy a ticket. They don’t – it’s just a condition of getting to point B quickly.

      Try using that argument with a transit officer! “I felt like I had already paid”.

      No one talks of safeguarding or forcing women to share intimate spaces with males who just feel like getting what they want.


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