Alice Sullivan, sociologist and head of research at the UCL Social Research Institute, former director of the 1970 British Cohort Study, examines the institutional capture that has made accurate collection of data on biological sex a contested issue. She describes the rapid shift in which stating that sex is binary and immutable—long an uncontroversial foundation of quantitative social science—became grounds for no-platforming, accusations of harm, and professional ostracism. Sullivan details her own experience of having an event cancelled by the National Centre for Social Research after organising a letter from leading survey researchers urging the Office for National Statistics to retain a clear sex question on the census. She argues that replacing sex with self-declared gender identity undermines the reliability of demographic data essential for measuring discrimination, crime, pay gaps and safeguarding. Sullivan links this capture to the influence of lobby groups such as Stonewall and insists that academic freedom and empirical integrity require resistance to the “no debate” slogan that seeks to place fundamental biological categories beyond discussion.
