Judgement to clarify biological sex ducked the issue. Anyone with a knowledge of biology beyond primary school level will know that biological sex is not simple. XY women? XX men?
During the run up to the 2024 general election many people mocked Keir Starmer for having difficulty stating what a woman is. In all likelihood he was defaulting to the legal definitions given his previous career in the legal profession. The law has struggled with this for many years, and has tried to clarify this with the recent rulings regarding the definition of a woman in the Equality Act 2010. What they came up with then, and reinforced the other day is woeful. Stating that it is the ‘biological sex’ as if there was a straight forward unequivocal biological definition demonstrates the lack of involvement of science literate people in the judgement.
The UK Supreme Court sought to clarify what a woman is with respect to the 2010 Equaiity Act. Lord Hodge summarised, “The unanimous decision of this court is that the terms woman and sex in the Equality Act 2010 refer to a biological woman and biological sex.” Unfortunately they neglected to ask biology what biological women and biological sex are.
Despite what many commentators believe, just stating that men and women can be easily defined by biological sex is far from simple. At a primary school level of understanding men have a penis, testicles, can grow facial hair and cannot give birth to children. A similar simplistic definition might say women have breasts, uterus, ovaries and can give birth to children. Unfortunately even the simple definitions can throw up lots of anomalies. There are women born without uteruses and can not have children. There are women who do not have breasts. There are women who can grow more impressive beards than some men. There are men who suffer from gynaecomastia which results in the growth of breasts. There are various causes of this including hormonal changes in men aged over 50, or during puberty, being overweight and certain medicines. There are also men who have extremely small genitalia that can be smaller than some women’s clitorises.
Harnaam Kau : https://www.standard.co.uk/news/uk/i-was-horrendously-bullied-bearded-lady-opens-up-about-life-with-facial-hair-a3584741.html
The Equality Act 2010, and the recent report that aimed to clarify the definition of a woman, both steered clear of stating what the biological definitions of a woman is. Sporting bodies have been struggling with the problem of the definition of sex for many years. Is it really so difficult? Unfortunately yes. Biology does not fit neatly into primary school ideas of sex.
Testosterone/oestradiol
Measurement of the levels of these steroid hormones is often suggested as a test for gender. Unfortunately these are far from being a reliable indicator of gender. People who have had the dubious pleasure of studying biochemistry may be familiar with the biosynthesis of these steroid hormones. Testosterone is the precursor for the synthesis of oestradiol. This means that testosterone is synthesised in women, which is then converted into oestradiol. In the average woman the majority of the testosterone gets converted to oestradiol by an aromatase enzyme. While some testosterone is normal in the blood of women it is typically at a low level. For some women this pathway is balanced differently.
There are various circumstances that can result in elevated testosterone levels in women. This can result in irregular menstrual periods, acne, male-pattern hair growth, deepening of the voice, and mood changes. With a female athlete undergoing a rigorous training regime from an early age it is possible that irregular menstruation might be overlooked as a consequence of the training and diet regime. For many women the cause of elevated testosterone can be polycystic ovary syndrome, adrenal disorder, intersex and other conditions.
Women potentially having elevated levels of testosterone does mean that a simple test is not an indicator of sex. There are also some men can have very low testosterone levels and some men having elevated oestradiol levels.
With hormones being of no use to determine ‘biological sex’ the next suggestion is usually chromosomes.
Chromosomes
The more attentive students of secondary school biology will have learnt that women typically have XX chromosomes while most men have XY. The Y chromosome contains a crucial gene for male development called SRY. More of this later.
This is the situation for most people. However biology does throw up various anomalies that make this simple definition unreliable. Most of these have been known about for many decades and be mentioned to medical and biology students.
XY women
Wait! What? In 1955 Gerald Swyer, an eminent consultant endocrinologist, published a report about male pseudohermaphroditism in which he detailed two women with an XY karyotype. These two ladies had normal female external genitalia, although one of the patients had an enlarged clitoris, but a normal vagina. Swyer syndrome people tend to lack significant ovaries or testes, however as the uterus is normal they can, and have, become pregnant using IVF. As many XX women require fertility treatment to become pregnant, this does not make XY women any less female.
XX men
No this is not part of the X-Men franchise. It is a condition sometimes referred to as 46,XX. In these individuals the SRY gene that drives the development of male characteristics is translocated to one of the X chromosomes. They are male although will typically have smaller testes, decreased height and be infertile.
There are various other sex chromosome permutations such as Turner Syndrome (X), Klinefelter syndrome (XXY), Trisomy X (XXX), Mixed Gonadal Dysgenesis (some cells XY and some only one X chromosome), 48,XXYY Syndrome (XXYY) and others. These Danish scientists have produced a reasonably accessible overview of the various genetic permutations.
Various other conditions exist where the sex of an individual does not fit into the simple binary notions of sex. Ultimately there is no simple biological definition of a woman when considering natural development. The issue of men or women feeling more comfortable with a different sexual identity is another matter, one which is best left to people who understand that aspect better.
Quiz time
When we pass judgement on whether an individual is male or female we rarely have the benefit of knowing their medical history. All we have is our opinions developed by expectations of what a man or woman should look like. Take a look at the following pictures and decide their gender before clicking below to reveal the answer.
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Caster Semenya – South African middle-distance runner and winner of two Olympic gold medals. She is a genetic female with 5α-Reductase 2 deficiency which results in elevated testosterone levels.
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Margaret Wambui – Kenyan middle-distance runner, winner of Olympic bronze medal. She has been diagnosed as having 46,XY.
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Sarah Gronert – German tennis player. She was born as intersex with both male and female genitalia.
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Erika Schinegger – 1966 ladies world champion downhill skier. He suffered pseudohermaphroditism. His genitals had grown inwards and at birth had been registered as female. After corrective surgery he became Erik Schinegger
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Dutee Chand – professional sprinter and a former national champion in the women’s 100 metres. Her hyperandrogenism condition leads to elevated testosterone levels. She was barred from competing for a while as a result of the rules at the time.
How well did you do?