When writing about gender and sex, it is important to understand to what these categories refer. Gender is a social construct and a social identity that encompasses an individual’s attitudes, feelings ...

Cis stands for "cisgender." It describes a person whose gender identity corresponds to the sex they were assigned at birth.

This story appears in the January 2017 issue of National Geographic magazine. To a degree unimaginable a decade ago, the intensely personal subject of gender identity has entered the public square.