How has the distinction between the notions “sex” and “gender” evolved? When did some people decide that everyone has an innate gender identity, and that it is that gender identity which makes you a man or a woman, no matter what sort of body you have? In just ten years, laws, company policies, education, sport, medical protocols, and the media have been reshaped to privilege self-declared gender identity over biological sex. Helen brings sanity to this heated debate.