There has been significant commentary on UK Supreme Court’s (UKSC) decision which held that the terms “man”, “woman” and “sex” under the Equality Act 2010 (EA) only refer to a cisgender man/cisgender woman. However, there is scope to assess what role separate grounds of ‘sex’ and ‘gender reassignment’ under the EA played in the court’s narrow interpretation of ‘sex’ as “biological” sex (birth-assigned sex).  

The UKSC stated that EA “recognizes sex and gender reassignment as distinct and separate bases for discrimination and inequality, giving separate protection to each (para 199).” According to the court, in this framework, sex would protect “biological” women, while gender reassignment protects transpersons. The alternative was to read that ‘sex’ under EA includes legal sex, that is, it provides protection to transwomen with Gender Recognition Certificates.  Other courts have also struggled with this – for instance, the South African Equality Court struggled to clearly identify discrimination against transpersons under enumerated grounds of sex/gender, broadly making a finding that the right to equality of a transwoman has been violated based on ‘gender identity’, albeit noting lack of a listed ground pertaining to transpersons (para 122).  Failing to identify discrimination against transpersons as falling under the ground of ‘sex’ encourages a larger reflection on how grounds under anti-discrimination law should be developed. Grounds such as gender reassignment, or even gender identity, may result in adoption of biological determinism in the interpretation of the ‘sex’ ground, i.e., reinforcing the norm that gender mirrors birth-assigned sex.

First, the presence of additional grounds like gender reassignment/gender identity may perpetuate biological determinism in a court’s interpretation of sex because courts may attempt to give them a distinct meaning, avoiding what they see as redundancy in legal language. The UKSC specially followed this route, interpreting sex and gender reassignment as providing distinct protections to cispersons and transpersons, respectively. This interpretive manoeuvre is not hard to achieve because sex discrimination prohibitions were traditionally introduced to provide protection to ciswomen. Sex became a ground through which ciswomen resisted invidious treatment based on their socially ascribed inferiority.  This built on feminist discourse that emphasised that while sex refers to biological differences between ‘men’ and ‘women’, gender refers to the social and political constructs of hierarchy between ‘men’ and ‘women’. What feminists fought against is essentially gender inequality under the ground of sex. At the same time, this framing of sex as biological (which remained part of the feminist discourse) gives fuel to those who argue that sex is something permanent and immutable, on which a person’s gender is based and a rejection of the assigned gender must be an anomaly. However, queer theory has challenged the feminist distinction between sex and gender, highlighting that sex is also a social construction. The male/female binary does not only underpin social assumptions about gender but also how bodies are sexed. The effect of the social meaning of ‘sex’ is apparent in the marginalisation/medicalisation of inter-sex bodies. Bodies and their social meaning are more intertwined, making it difficult to separate the ‘biological’ from the ‘social’; sex from gender.

Second, additional grounds of gender reassignment/gender identity obscure how transpersons are essentially experiencing sex-based discrimination. The differential treatment on account of the reassignment process or perceived gender identity is because of non-conformity with the stereotypes associated with binary understandings of sex (whether in terms of biological attributes or social assumptions). Even the creation of gender identity as a specific ground for protecting transpersons can be harmful because it assumes that only transpersons have a gender identity, when it is a universal characteristic. Everyone has some perception of their gender, or a gender identity.

Third, if only sex as a ground exists, it may lead to the expansion of the category to include transpeople (such as in the case of India and United States). The Indian Supreme Court achieved this in a more meaningful manner where it identified sex discrimination as broadly a protection against sex stereotyping (which both ciswomen and transpersons suffer). These decisions may not be spelling out a social constructivist understanding of sex, but this does disturb the differentiation between sex/gender/gender identity, making the category of sex appear more expansive, less tied to biology.

Thus, while separate grounds like gender reassignment/gender identity do not preclude the court from reading sex as a ground expansively to include ‘acquired’ sex, there is a possibility that the court may resort to a narrow interpretation of sex. The courts may proceed on the assumption that transpersons have some protection under the add-on grounds. But an interpretation limiting sex to birth-assigned sex ultimately reinforces ‘cisness’ as the norm.