>>11375115 Consider a parallel distinction – between food and cuisine. There is a clear sense in which food is a natural category whereas cuisine is socially constructed. For the differences between French cuisine, Thai cuisine, and so on obviously reflect various human conventions and culturally contingent circumstances.
All the same, there are obvious limits to this variability, and certain features that are true of all cuisines. For example, all cuisines are going to provide at least some significant nutritional value. The reason is that even though a cuisine is always more than just food, it is also always at least that. Vary the use of spices, the kinds of meat favored, the manner of presentation, etc. all you like, you are always going to get something that provides nutrition. Cuisines do this in a specifically human way because they reflect the creativity that follows from our rationality, but they nevertheless always build on rather than replace the raw biological function served by food.
Now, sex and gender as traditionally understood are like this. What expectations follow from being either “male” or “female” in the gender-related senses of these terms may vary somewhat from culture to culture, but they also traditionally have always been taken to reflect merely different, distinctively human ways of being male or female in the biological or sex-related senses of the terms. And merely to note that gender is socially constructed does not suffice to show that that traditional view is mistaken. You might as well argue that because cuisine is a socially constructed category, it follows that there could be cuisines that serve no nutritional end but have only wax, or Play-Doh, or the like as ingredients.
Arguably, it is because some activists rightly perceive that gender is bound to be less fluid if sex differences are natural that they want to cast doubt on the latter thesis – however beyond reasonable doubt it is.