For years at 13.7, Barbara J. King has been writing about what she calls the spectrum of gender expression, and "the fact that gender identity isn't only — or even mostly — about biology and that it's most certainly not reducible to the sex one is assigned at birth." That's an especially important lesson in light of new research that identifies one of the sources of prejudice against transgender individuals: the (mostly mistaken) belief that men's and women's stereotypical characteristics do, in fact, come down to some immutable feature of one's biology.

Transgender people like myself have consistently tried to promote the idea that sex and gender are two distinct qualities that every human possesses. Meanwhile, our adversaries believe that sex (chromosomes or genital morphology at birth, or both) completely determine what our gender should be...and if we deny that, we are committing deception.