The battle between sex and gender
Peter Vasterman dissects the Dutch Transgender Law, the works of Kathleen Stock, Debra Soh and Helen Joyce, and the consequences of self-identification for women, science and the consulting room.
A law that scraps biology
The Dutch Transgender Law provides that the sex stated on the birth certificate may be changed on the basis of a declaration alone. No diagnosis, no physical trajectory, no waiting period. Vasterman summarises the core drily: "the only thing that counts in the new law is the 'experienced gender identity'". With that, the legal concept of sex is decoupled from the biological. It looks like an administrative adjustment, but it is a shift in what a woman or man legally is — from a perceivable trait to an inner feeling.
Three philosophers who dissect the ideology
Vasterman discusses three books: Material Girls by philosopher Kathleen Stock, The End of Gender by sexologist Debra Soh and Trans by journalist Helen Joyce. None of these authors denies that trans people deserve rights. What they contest is the claim that an inner "gender identity" literally makes someone a woman or a man. Their work forces the distinction back: sex is biological, gender is a set of social expectations, and self-identification changes neither. It is precisely this distinction that the Dutch law erases.
Biology matters — also in behaviour
The claim that gender differences are purely social construction does not hold up against what animal and human research show. Fetal testosterone influences play behaviour, occupational preference and interests. Soh dissects this in detail: the image of a "blank slate" on which only culture writes does not hold. Vasterman draws the logical conclusion: if sex produces biological difference in behaviour, the claim that "being female" is a purely social label is an ideological claim, not a scientific one.
A new group of girls changes the picture
Since 2012 huge numbers of teenage girls have come forward at gender clinics without any history of gender unease in childhood. They discover on TikTok, Tumblr or in friend circles suddenly that they are "actually a boy". This profile does not fit the classical patient for whom the Dutch Protocol was written. Vasterman sees here where Lisa Littman's hypothesis of social contagion empirically gains ground. The claim that dysphoria is always innate and always persists breaks on this cohort.
Women's spaces and sport under pressure
As soon as "woman" is redefined as "anyone who feels that way", the legal basis of women-specific facilities evaporates. Vasterman sums up: "It is not just about separate toilets, but also about changing rooms, prisons, women's shelters and of course sport." In each of these domains there are safety or fairness considerations explicitly built on biological sex. Joyce documents in her book how British and American policy has been shifted in years without public debate, with concrete harmful incidents as a result.
Science silenced
The taboo on criticism works stiflingly on research. Stock was bullied out of her university by students and colleagues. Researchers who raise questions about puberty blockers, social contagion or comorbidity get the label "transphobic". Vasterman describes that "many subjects have been declared taboo". The irony: in virtually every medical file where there is so much uncertainty, science demands more research. Here the question itself is criminalised.
Diagnostics based on self-report
Vasterman points to a fundamental diagnostic problem: "Not only is establishing gender dysphoria problematic, because everything depends on what the person says themselves." There is no objective test, no biomarker, no scan. The diagnosis is what the patient tells — preferably in a story that fits the existing criteria. In adults this can be an acceptable trade-off. In thirteen-year-old girls, often with autism, eating disorder or depression, it opens the door to irreversible interventions based on self-report.
Detransitioners as blind spot
A growing group of ex-patients — especially young women who were given testosterone and mastectomy in their teens — speak publicly about regret and lasting physical damage. Trans activists respond with denial or trivialisation. Vasterman calls this a stifling effect "that not only damages the social position of women, but also has stifling effects on science". Whoever pushes these voices aside excludes precisely the cohort that has the most to say about treatment outcomes.
What is at stake here
Vasterman makes a synthesis: the battle is not about whether trans people exist or deserve rights. They do. The battle is about whether a felt label overrides the actual biology of a body — legally, medically, in sport, in language. The three books he discusses say no to this, on clear scientific and philosophical grounds. The Dutch law says yes, without that debate ever having been properly conducted. The difference between these two positions will structure every policy discussion about changing room, clinic, sport and consulting room in the coming years.