It's time to celebrate the fact that there are many ways to be male and female

Research published yesterday, showing that brains don't come in male and female forms, fits with what we know about gendered behaviour

It's the first thing we want to know when a newborn arrives. We state it on every form we fill out. We mark it with pronouns, names, clothing, and hairstyle. It's the first thing we register about a person.

Sex categories - whether you have female or male genitals - are fundamental for reproduction. They are also the principal way we carve up the social world. No surprise then that scientists and the general public alike often assume that sex categories are no less essential to how we think, feel, and behave, taking it for granted that there are female and male natures subserved by a "female brain" and a "male brain", respectively.