While biology shows us gender can be fluid, our brains struggle to see it that way

Robert Sapolsky in Nautilus:

Biologists have long known about exceptions to the boring, staid notion that organisms are, and remain, either female or male. Now our culture is inching toward recognizing that the permanent, cleanly binary nature of gender is incorrect.

Along with the high-profile Caitlyn Jenner, and Emmy-nominated actress Laverne Cox, America has seen openly transgender individuals serve as a mayor, state legislator, judge, police officer, a model for a global cosmetics brand, and a high school homecoming queen. Even amid the appallingly high rates of discrimination and violence against transgender individuals, there is a growing recognition that gender designation need not be permanent.

Many people are questioning whether there is even such a thing as “gender.” These are individuals whose psychosexual self-image may be of both genders, a third gender, no gender, or whose visceral perception of the social world does not include implicitly seeing people as gendered.

This new continent was formalized by as august and ancient an institution as Facebook, which offers 58 gender specification options on one’s profile page. These include Agender, Bigender, Intersex, Gender Fluid, Gender Questioning, Non-binary, Pangender, and my two favorites—Two-spirit, with a vaguely Native American grooviness to it, and Other, which basically implies that, Whoa, Nellie, we’ve barely scratched the surface!

More here.