This dataset consists of 126 semi-structured (including 5 unstructured interviews) and a public survey to explore current understandings of legal sex/gender and attitudes towards its decertification. Decertification is used in this project to mean that people would no longer have a legal sex or gender (birth certificates, for instance, would no longer register a baby’s sex). Interviews were mostly conducted in-person prior to covid. After March 2020, they were undertaken via online platforms. The transcripts include interviews with a wide range of stakeholders exploring the implications of reform to legal sex and gender certification. Interviews also addressed organisations’ current practice in relation to the use of sex and gender categories, their response to gender identities such as agender and nonbinary, the challenges that innovation in this area face, and the question of how an identity-based approach to gender could combine with one attentive to structural gender inequalities. Predominantly semi-structured interviews were conducted with 1) Members of different publics using tailored interview methods to explore continuity, change and disruption in understandings and interpretations of gender (and its relationship to sex) across social and legal contexts; 2) public bodies, service providers, NGOs, regulatory bodies, religious communities, trade unions, legislative drafters, academics, and others working in related fields. A number of interviews were carried out for this research project that have not been archived. This is for several reasons, including in a few cases technological failure. However, one recurrent reason for non-archiving relates to the inability of organisational interviews to be sufficiently anonymised and the currently contentious nature of gender/ sex law reform discussions. In some cases, despite giving initial permission to archive when the interview was carried out, interviewees subsequently requested that their interview not be archived. The dataset also consists of a survey which explores wider public perceptions of reforming legal sex and gender. The ‘Attitudes to Gender’ survey was conducted as part of the ‘implications for the wider public’ strand of the Future of Legal Gender research project and focused on asking questions to gain a better understanding of what legal sex and gender status means for people, and whether it matters to individuals in their everyday lives. The survey ran from October to December 2018 in partial overlap with the UK Government’s public consultation on potential reform of the Gender Recognition Act 2004 (GRA) in England and Wales. We chose to develop the survey questionnaire ourselves rather than use pre-existing measures so we could ensure the survey mapped well onto the overall aims and objectives of the project. Sampling was opportunistic. We received 3101 usable responses to the survey. Some demographic data was collected and analysed (e.g. age, class, ethnicity, sexual preference, religion) but removed from this SSPS data set for anonymity purposes.Feminist activists and scholars have long questioned the idea that gender is anchored in natural biological distinctions, arguing instead that concepts of masculine and feminine, and what it means to be a woman or man, are socially generated. More recently, some transgender and intersex activists and scholars have developed these claims further, arguing that people's gender identities should not be restricted to the sex formally recorded at birth. As many people seek to live in ways that do not correspond to stereotypical notions of their gender or otherwise diverge from the sex and gender assigned them, law in different jurisdictions has responded. Gender-neutral laws, procedures for gender transitioning, and legal decisions recognising the possibility of nonbinary gender identities unsettle traditional legal regimes based on two, biologically fixed, socially differentiated genders. Yet, while reform initiatives internationally gain momentum, they tend to be limited in two key respects: first, they typically adopt an ad hoc or incremental approach to legal gender identity structures; second, they focus on legal accommodation of gender minorities within existing classificatory structures rather than more general reform. Legal and policy developments, the gender activism surrounding them (with all its internal disagreements, including over the meaning of biological sex), and the rapid upsurge of wider interest and concern about how to regulate and recognise gender identity have brought a more fundamental question to the surface: should sex remain a legal status assigned at birth; and what would be the implications of reforming this? Our project addressed this question, focusing on the legal jurisdiction of England & Wales, but drawing also on developments in Scotland and overseas. Research was organised into three consecutive work packages. The first drew on international developments and activist arguments to outline possible options for reform (for instance, birth certificates with more than two sex or gender options; allowing people to choose a legal gender on maturity; or modes of regulation that approach gender and sex in ways that are more akin to the legal treatment of sexual orientation and race which are not formal statuses in English law while still constituting protected equality grounds). The second work package focused on “decertification” as one specific reform proposal. It explored what decertification would mean: for gender-differentiated provision, such as single-sex schools, domestic violence shelters, and women's groups; for diverse equality agendas; and for how gender and sex are codified in law. This second work package also explored public attitudes to reform, and what this can tell us about the significance of legal gender in everyday life. The final work package drew the research together to understand key points of disagreement and tension regarding decertification as a law reform proposal in a British context. In this work package, we also produced a series of prototypes exploring legislative principles for decertification law reform. Decertification – the dismantling of legal sex status - involves removing sex from birth certificates so people no longer have a legal sex or (corresponding) gender status. It also entails other changes to regulatory laws that rely on sex and gender-specific terms. Adopting a multi-methods approach, research data included a public survey, online documentary materials, and interviews with NGOs, policymakers, equality specialists, trade unions, legislative drafters, and members of different publics. Through meetings, workshops and the prototyping of legislative principles, the project actively engaged stakeholders in shaping and discussing research questions, analyses, and the possible legal form that decertification could take. Research findings, analysis and conclusions are disseminated through special issues (in refereed journals), other refereed journal articles, our website, blog posts, presentations, and social and mainstream media. A detailed public report was produced at the end of the project, Cooper, D., Emerton, R., Grabham, E., Newman, H.J.H., Peel., E., Renz, F. & Smith, J. (2022) Abolishing legal sex status: The challenge and consequences of gender related law reform. Future of Legal Gender Project. Final Report. King’s College London, UK.

We conducted 156 interviews with public bodies, service providers, NGOs, regulatory bodies, religious communities, trade unions, legislative drafters, and others working in related fields to explore single-sex and gender-specific provision; the implications of decertification for social justice and equality; and the challenges raised for legislative drafting. Interview participants came from sports, local government, equality organisations, schools, domestic violence shelters, and women, trans, and intersex campaigning organisations, among many others. Our rolling research programme focused on sectors and organisations dealing with legal gender in everyday life. For example, we identified a range of organisations, including regulatory and governmental bodies, who were responding to new gender identities and gender transitioning, facing political pressure to retain the legal language of sex, and/or advancing policies to address structural gender inequality. This purposive approach to interview recruitment was designed to enrich our analysis of decertification as a prefigurative law reform proposal. Interview participants were invited because of their relevant professional capacity. Although we did not seek a demographically representative sample, our decisions about which organisations to interview were informed by the importance of attending to diverse experiences, and the impact of social relations of gender, socioeconomic class, race, disability, religion, sexuality, age, and nationality on people’s lives. Our sampling approach also varied by sector. For domestic violence services, all publicly listed single-sex services in England and Wales were approached to gauge interest in interview participation. Elsewhere, we contacted organisations identified by ourselves or others as innovators, as actively engaging with the changing politics of gender, or as operating in fields, for instance, refugee support services, where decertification might raise distinctive or complex issues. The interviews were in-depth and semi-structured, with questions designed to elicit views and feelings towards decertification as an imagined future law as well as participants’ experiences of ‘soft decertification’ in their policy and practice. Interviews for all parts of the project were conducted faceto- face, in person, via video conferencing software, or by telephone, where this was the interviewee’s preference. Interviews were transcribed verbatim either in full or in part, depending on the content of each individual interview. Our feminist psychologists explored legal gender in everyday life through a survey and in-depth interviews with members of the public. In 2018, we launched an online survey, ‘Attitudes to Gender’, which was publicised and circulated via stakeholders, project networks, and other contacts. The survey was open to anyone 18 or over regardless of their locations. Our aim was to generate wide-ranging understandings of public attitudes to gender and to legal gender reform. The survey was structured in three sections: demographic information about participants; views on gender in everyday life; and attitudes towards legal gender and options for reform. We received 3,101 usable survey responses, 2,555 of which were from the UK. The survey encouraged participants to reflect on legal gender by rating and commenting on opinion statements. Our aim was to include perspectives of people with diverse backgrounds in both the survey and interview components. As the recruitment process continued, these efforts were targeted towards groups underrepresented in our survey and interview samples (e.g. men). Our psychologists followed-up the survey with interview data. We conducted 44 semi-structured, one-to-one interviews with members of different publics to further explore their understandings, interpretations, and experiences of gender, and their views on reforming how sex and gender are used as legal categories. We initially recruited interview participants via expressions of interest on completion of the survey before extending invitations using a range of methods. We circulated interview recruitment material via social media platforms such as Twitter, and sent emails to charities, organisations, and community groups with an interest in gender, faith, law, or equality. The survey was open to anyone over 18 regardless of location to capture diversity of attitudes. Sampling for interviews was purposive – to capture different understandings and perspectives on reform of sex/ gender categories, and to study organisational innovation and engagement in this field.