Why New Zealand law needs clear definitions of woman and man
Thursday, 11 June 2026
Sue Middleton is an emeritus professor of education at the University of Waikato. She has researched and taught courses on women, sexuality and education.
OPINION: The Legislation (Definitions of Woman and Man) Amendment Bill proposes to define “woman” as “adult human female” and “man” as “adult human male”.
The Bill’s use of “adult” is problematic. In Aotearoa, there is no longer a single “age of maturity” – it varies. The legal “age of consent“ for sexual intercourse and/or marriage is 16; for leaving school or holding a driver’s licence it is 16; it is 18 for joining the military, betting, drinking in a bar and voting in elections. In 2024, the UK Supreme Court ruled that in that country’s law, “woman” refers to a female of any age. Despite this ambiguity, the Bill’s use of “male and female” makes its intent clear: Aotearoa-New Zealand law requires a definition of sex as biological. In the mid-late twentieth century, when our Human Rights and related laws were drafted, the words “man and boy, women and girl” were commonly understood as referring to biological males and females respectively. In other words, they referred to sex. This definition will apply to all statutes where these words are used.
The Bill is an acknowledgement that the protected category of sex in the Human Rights Act 1993 and related legislation is now under threat. This threat comes from concerted efforts to insert the language of “gender ideology/ theory” – a disputed belief system – into law, policy and everyday language. In countries where this has been achieved, such as Australia, the rights of women to single-sex facilities, sports, organisations and services have been removed and are currently subject to litigation at the highest levels.
Securing this existing right does not, as certain MPs and groups have claimed, “erase trans people”. In 2024, referring to proposed reforms of the UK’s Equality Act, Baroness Kishwer Falkner, former chair of the UK’s Equality and Human Rights Commission, explained that defining sex as biological would not remove existing protections for trans people; it would, rightly, remain unlawful to discriminate against anyone on the basis of gender reassignment when it came to housing, employment or provision of goods and services. It would not stop groups offering trans-inclusive services and spaces. But clarification would strengthen the existing provision to provide single-sex spaces such as in prisons and rape crisis centres.
From around the mid-twentieth century, the words “sex” and “gender” were often used interchangeably. In The USA, Judge Ruth Bader Ginsberg was advised that her constant use of the word “sex” when advocating for women’s rights was disturbing to her conservative male colleagues, so she should use the grammatical term “gender” instead. Since then the word “gender” has acquired different meanings.
Transgender historian Susan Stryker writes: “Gender is considered to be cultural, and sex, biological. It’s usually a safe bet to use the words man and woman to refer to gender just as male and female are used to refer to sex”. She is correct that “gender” is a cultural construction. But she uses it here not in its sociological sense (as social roles and stereotypes) but in a psychological sense, as personal identity. Transgender people often describe their “gender identity” as a deep sense of dissociation from their bodies – “born in the wrong body”. But, most of us do not “have” a “gender identity“ at all. We are our male or female bodies.
The Bill is about “sex” not “gender”. It is a response to activist redefinitions of “man and woman” as subjective and personal – as identity - rather than objective biological, categories. It is a reaction to the offensive language used for female bodies when biological definitions of women (and mothers, and lesbians) are denied: “People with uteruses”, “birthing parent”, “chest feeder”, “same-gender” (not ‘same-sex or homo-sexual) attraction. How have the words “woman” and “man”, sex and gender become so contentious?
Sex, Gender and Identity
Biological definitions of sex centre on mammalian species’ (including human) reproductive capacity.
Sex is binary because the existence of rare intersex and bodily characteristics (DSDs) do not constitute a “third sex”. Evolutionary biologist Colin Wright explains: “When biologists claim that ‘sex is binary’, they mean something straightforward: there are only two sexes. Males have primary reproductive organs organised around the production of sperm; females ova. Because there is no third gamete type, there are only two sexes that a person can be. Sex is therefore binary.”
Theorised at the level of a species, this definition does not imply that every individual body is capable of reproduction or producing gametes – variations in sexual development, including reproductive capacity, can occur in utero, as a result of medical conditions, or of medical or surgical interventions.
As Wright explains, “the binary nature of sex is compatible with sex ambiguity because ambiguity itself is not a third sex”. Disorders of Sexual Development (DSDs) are variations within the male and female categories. Fewer than 0.18% of people have “intersex”/ sexually ambivalent bodies and their Human Rights are currently protected by the category of sex. Sex is observed and recorded at or before birth.
Since around the turn of the century, activist groups have twisted (or “queered”) the previously taken-for-granted language of sex. For them, subjective, self-diagnosed, “gender identity” deserves priority – in law, in social policy, in sport, in healthcare, in sex-segregated facilities. A woman is anyone who “identifies as” or “feels like” a woman.
Medical and/or surgical treatments are no longer required: subjective identity has primacy. Challenging this is cast as “hate”; critique is to be suppressed and dissenting professionals – therapists, doctors, teachers - punished by blacklisting or dismissal. Common mantras are: “Trans women are women, no debate” and “Trans rights are human rights”. This rests on “gender ideology” (or “gender theory”) - a disputed belief that everyone has a “gender identity”. This involves a shift not only in the everyday meaning of sex, but also common understandings of gender.
Until around a decade ago, “gender” was commonly understood as a sociological, not a psychological (individual identity), category. In this sociological sense, gender refers to the stereotyped roles, expectations, behaviours and personal qualities expected of men (males) and women (females). These vary historically and culturally. For example, Samoan traditions included a third gender, fa’afafine – males who presented and behaved “as if” they were women (but were clearly not biological women). During the 1970s-90s, “second wave” feminists worked to abolish “gender stereotype”. “Butch lesbians” were girls (females) who presented as “masculine”, and “effeminate” boys (males) might dress and behave in ways culturally stereotyped as “feminine”. But Butch lesbians were women (female), and effeminate boys men (males). Late twentieth century feminism fought to free up both sexes from rigid expectations for appearance, activities, roles and persona characteristics.
The challenge to sex-based rights arises when “gender” is used in a psychological sense - as an individual’s identity. Until around 2010, this psychological notion of “gender identity” was virtually unknown beyond the medical context in which it was “invented”.
In the 1950s medical scientists performed non-consensual surgeries to reconfigure ambivalent infant bodies according to binary norms. They imported the word “gender” from linguistics to name a condition in which a person’s “psychological sex” – their feeling of being masculine or feminine – did not conform to the category to which doctors had assigned them. Amongst biologically “normal” infants, such psychological gender incongruence was rare and seen mainly in boys. Today this is known as gender dysphoria. Recent international data, eg from the Cass Review in the UK, showed an exponential increase in the numbers of girls, the vast majority of whom were same-sex attracted, presenting to gender clinics wanting to be, or claiming that they innately were, boys.
Identity is a psychological term. Adolescence is characterised by an “identity crisis”. The (contested) belief that everyone develops a “gender identity” is what is meant by “gender identity ideology”. Educationists have observed that when children are presented with a range of gender identity categories, they might identify with, and describe themselves, in those terms. International research on child and adolescent ‘gender transitioning’ has shown the devastating impact of social media in convincing vulnerable young people that same-sex attraction, gender non-conforming personalities and appearance, suggest they were “born in the wrong body”, a condition requiring lifelong medical and/or surgical intervention. Autism, eating disorders, abuse and mood disorders are over-represented in these populations.
Adults who have chosen the painful medical and/or surgical “transition” pathways deserve support. Aotearoa-New Zealand has a proud record of gender non-conforming people, including those who have identified as transsexuals. Examples include Carmen Rupe, whose Balcony Cabaret helped launch the careers of experimental theatre groups such as Red Mole; and Georgina Beyer, the world’s first transsexual MP and mayor. I condemn the abuse and negative discrimination described by transsexuals, people who present and describe themselves as non-binary or as one of the other rapidly multiplying identity categories within the “transgender” lexicon. I support clarifying the legislative protections of people who do not conform to the bodily norms and/or the sociocultural stereotypes for their sex. This can be done without undermining the sex-based rights women currently enjoy.
A science-based definition of sex is essential if we are to defend our current rights as women – the female sex. We need it to secure our female-only spaces (including spaces where women undress); services (health, counselling, intimate care, refuges) and activities (sports). A biological definition of sex is also needed to defend sexual orientation as a protected category. The rights of lesbians and gay men to be “same-sex” (homo-sexually) attracted are threatened when sex becomes confused with gender. Submissions on this Bill close on July 2. I urge all Kiwis to have their say.