This book, by an American biologist, addresses, in an accessible yet serious and scientific way, the claims made in recent years that: 'sex is a social construct'; there are many 'non-binary' people who are neither male nor female; there are 57 (or is it 157?) varieties of gender rather than the traditional 2; people can cease to be male or female and become, rather than just take on the form and appearance of, the opposite sex by drugs, surgery or simply announcing that they now identify as a different sex, hence a man can have a womb and give birth, or a woman can have testicles.
There are many aspects and implications to these questions. In this quite short, 200 page book, 'Binary', the author Zachary Elliott concentrates on addressing, by genetics, anatomy, physiology and reproductive function, the underlying biological realities of what sex is, how we can tell what sex someone belongs to and whether it is possible to change it.
Thus, this book discusses chromosomes, gametes and gonads, all of which are defined for non-biologists like me in a helpful Glossary at the end of the book.
There is little here directly on the practical implications e.g. should someone born in a male body but who feels they are really a woman be allowed to compete in women's sports, walk around naked in a women's changing room, or be held in a women's prison if they commit a crime? Nor does it address directly the psychological roles in all this of social media, autogynephilia (worth looking up if you don't know what that is), autism or reaction to past sexual abuse. However, the information in 'Binary' is important background to addressing these questions. I recommend interesting books on these wider issues at the end of this review.
Nor does 'Binary' discuss the threats, discrimination, verbal abuse and sometimes violence endured by some on both sides of this debate, both those who consider they are 'trans' and those like JK Rowling in the UK and Riley Gaines in the USA who publicly challenge the claims of the 'trans' movement.
Likewise, this book will not answer a question that I expect will concern future historians, as to whether it is coincidence that the 'trans' issue, previously a fringe concern, suddenly took on such enormous, potentially career and reputation destroying, importance around the same time that George Floyd/ Black Lives Matter similarly exploded in 2019-2020, and that all this coincided with the Covid-19 lockdown.
However, if we are to address those issues, it helps to understand the underlying biological reality. Zachary Elliott's book lets us do that.
While many, especially microscopic, creatures still multiply without sex, male and female sexes as a means of reproduction evolved more than a billion years ago, making them older than the brain. They are found in animals and plants, although some plants, and a few animals such as Earthworms, have the reproductive organs of both sexes in the same individual. Some species of fish, amphibians and reptiles can change from one sex to the other either as a regular part of their lifecycle or in response to changes in their environment.
In mammals, including humans, the key genetic determinant of being male is the presence in every cell of the body of a 'Y' chromosome, males normally having 46 Chromosomes including an X and a Y, while females normally also have 46 Chromosomes but with two Xs. [This is why 'Tortoiseshell' cats, really a combination of black and ginger tabby, are almost always female. The genes for black fur and ginger tabby are both carried in the same part of the X chromosome. Hence, tomcats, who only have one X chromosome, may be either black or ginger tabby, but only female cats, with their two X chromosomes, can be both at once.] Birds have a similar but different system involving so-called W and Z chromosomes.
However, the author argues that while X and Y chromosomes are very important in determining sex, they are not the same as sex.
While rare, it is possible for humans to be born with a chromosome more or less than normal. Combinations of XXY, XYY or a single X or Y are possible. Occasionally, also, someone is born with a normal combination of XX or XY chromosomes, but other genetic abnormalities mean there is a drastic under or overproduction of chemicals called hormones that affect the body's development as male or female. Thus, about 1 in 20,000 men actually have two X chromosomes and no Y.
These unusual combinations, between them amounting to up to 1.7% of births, are genetic reproduction misfiring. They are often associated with inherited health problems and sometimes infertility. However, Zachary Elliott denies that anywhere near that number are neither male nor female. In only about 0.02% of cases, do such abnormalities result in genitals so unusually sized, shaped or positioned (including being located inside rather than outside the body) that one cannot tell a baby's sex by external observation.
The author contends that even among this anomalous 0.02%, sex can almost always be biologically classified as male or female by gonadal tissue (the part of the body that makes either eggs or sperm), genes or internal genitalia.
Reproduction is so essential to the survival of any species, and sex so crucial to reproduction in vertebrates, that the author believes over the last billion years our bodies evolved so that even if born with almost any possible genetic abnormality, we develop down either one path or the other, and become, in reproductive potential, either male or female, but not both, and not neither.
None of that by itself tells us the morally right thing to do if a man called Stan puts on lipstick and suspenders and announces 'I am now Loretta the lady' and becomes upset or threatening unless addressed as such and allowed to use the Ladies' Washroom and compete in women's sports.
What it is in the interests of Stan/Loretta, other users of the Ladies' Washroom, and of society, to do in this situation, and how to balance these interests, is partly a question of courtesy, practicality and safety of all concerned, not just biology.
However, a starting point to get to the right answer surely is, as Zachary Elliott writes:
'One's sense of self-determined sex cannot even be tested with scientific method. It uses the veneer of science.'
Thus, Stan will in reality always be a man to science, even if he likes to behave in a traditionally feminine way, and even if the last Editor of the Scientific American could not see this.
******
Good books on the wider social and moral implications include 'Trans' by Helen Joyce and 'Unfair Play' (about effects in sport) by Sharron Davies. It is also worth searching for the testimonies both of detransitioners, such as Chloe Cole's interview on YouTube with Jordan Peterson, and of 'trans widows', including Shannon Thrace's book 18 Months. Also good are JK Rowling's Tweets on the issue and the 'Stan wants to be Loretta' scene from the Monty Python's 'Life of Brian' film.
Frankly, I have not yet come across anything as impressive putting the 'trans' side of the argument. If I do, I shall add details to this review for balance.