It's a long article, so a TL;DR using some quotes might help: > But from a biological perspective, what makes an observable physical characteristic ‘male’ or ‘

It's a long article, so a TL;DR using some quotes might help: > But from a biological perspective, what makes an observable physical characteristic ‘male’ or ‘female’ is not its association with gender, but its association with something more tangible: the production of one or other of the two kinds of gamete > In human populations, there are plenty of individuals whose sex is hard to determine. Biologists aren’t blind to this. The definition of biological sex is designed to classify the human reproductive system and all the others in a way that helps us to understand and explain the diversity of life. It’s not designed to exhaustively classify every human being, or every living thing. Trying to do so quickly leads to questions that have no biological meaning. > Human societies can’t delegate to biology the job of defining sex as a social institution. The biological definition of sex wasn’t designed to ensure fair sporting competition, or to settle disputes about access to healthcare. Theorists who want to use the biological definition of sex in those ways need to show that it will do a good job at the Olympics or in Medicare. The fact that it’s needed in biology isn’t good enough. On the other hand, whatever its shortcomings as an institutional definition, the concept of biological sex remains essential to understand the diversity of life. It shouldn’t be discarded or distorted because of arguments about its use in law, sport or medicine. That would be a tragic mistake.