sure thing! It’s a fairly mainstream “trans-inclusive” opinion that while sex is still biological (which is to say, binary, “real,” outside of social opinion, it exists in nature), gender is socially constructed. This frames being transgender as having a socially constructed gender that ‘conflicts with’ biological sex. This conforms to mainstream psychiatric models of transgenderism, which frames trans people as having an identity disorder or something psychologically wrong with us that makes us ‘want to have a gender that is different from our biological sex.’ It is a handy way of conceding that gender is social while still maintaining the belief that sex is a real biological thing. It is very common among doctors, cis allies, policy documents about trans inclusivity (the ones I’ve read, anyway), and is also a common opinion among trans people in my experience.
I really dislike this framing for several reasons - one is that it is in fact arguing that gender is biologically based by tying it to our ‘natural sex’ (if our gender ‘conflicts with’ our sex, then gender is still biologically based, and if the reason you want to change your gender is because of mental illness, then a desire to change one’s gender can only be gained through psychological abnormality). It also maintains sex as something that is real, unchanging, natural, and universal across space, time, and culture. It is none of those things -
sex can change (HRT, surgery, and so on changes our sex, in fact it’s called ‘sex reassignment surgery’ and HRT is comminly understood as initiating a ‘second puberty’),
sex is not binary - a belief that it is binary is what constructs the category of ‘intersex,’ ie people who don’t fit this supposed universal sex binary, and this construction produces medical violence against intersex people by positioning them as medically defective/abnormal,
sex is not ‘real’ in the sense that the category of ‘sex’ is a social construction that bundles a complex series of properties of the body (external genitals, reproductive organs, hormones, chromosomes, gametes, etc) together by claiming they always 100% coincide with each other and form a coherent whole (this is not true, ‘sex’ is a spectrum because sex refers to many, many things). You can read the work of Julia Serano, a trans biologist who has published many open access essays on this subject. I believe she recently published a piece critiquing the idea that gametes are binary
The process of assigning sex at birth does not even follow this supposed scientific fact properly, because we don’t run chromosome checks on infants, we don’t do ultrasounds on them to see what their internal organs look like, we don’t measure their hormone levels, and so on. Sex assignment at birth is a social process of doing a quick genital inspection of infants and then writing down their sex on birth records based on that inspection, and if those external genitals don’t conform to binary understandings of sex (eg the infant is intersex), these genitals are surgically altered to fit this binary model. I believe Adamson describes this in Beyond the Coloniality of Gender as preparing children for a life of ‘good heterosexual sex’ (this is a paraphrase, I don’t remember the exact quote)
Because sex is a socially constructed category, it is not universal, because social constructs are dependent on the social context they arise in. I’ve read a number of papers from postcolonial/decolonial scholars in particular critiquing this supposed universalism as a form of colonial domination (María Lugones’ Coloniality of Gender, Sally Engle Merry’s Colonial and Postcolonial Law, Boris Bertolt’s The Invention of Homophobia in Africa, Jenny Evang’s Is Gender Ideology Western Colonialism?, B Binaohan’s Decolonising Trans/Gender 101. These last two aren’t postcolonial works but they’re very instructive for understanding sex assignment as a deeply oppressive and non-scientific practice: Heath Fogg Davis’ Sex Classification Policies as Transgender Discrimination: An Intersectional Critique and Toby Beauchamp’s Going Stealth: Transgender Politics and US Surveillance Practices)
essentially, “sex is biological, gender is social” is a massive cop-out that still accepts the framing of binary sexual biological legitimacy, which is the foundational belief that produces transphobic violence and discrimination in society. I really like Judith Butler’s framing of it Bodies That Matter: if sex is this supposedly biological reality that can’t change, but our understanding of sex is only always in reference to our social interpretation and application of it in the world (eg gender), then sex is also socially constructed
