Gender (n.) - How many genders are there?
A class or grouping of grammatical words in a language. English has no grammatical gender, but does have three gendered pronouns he, she, and it.
It is also used interchangeably with sex.
What is it? How many are there? Why does it matter? And who caused this mess?
Laci Green's gender video: https://youtu.be/t8S4hMjFTSI
Computerphile Binary video: https://youtu.be/thrx3SBEpL8?t=6m15s
History & Etymology:
We’re going to start back with the Proto-Indo-European root gene- which meant “to give birth or beget” This initial relationship with birthing would seem to imply a very close tie to sex and genitals in the development of the word gender, but even to my surprise, that wasn’t the case.
Instead of taking a route through separating men and women by their intimate bits, it became the word genus which still means the same thing today, “race, stock, family, order or species.” It became a word that sorts things into any number of groups.
As Latin word moved in to Vulgar or Popular Latin changed and that became Old French genus became genre, another word that moved directly into english that differentiates groups of things. Due to a quirk of Old french another variant of this word came about gendre.
And as many words it finally came into english during the norman invasion of england, and became gender. At this time it was used purely in reference to grammatical classes of words, and it remained this way till late in the 20th century.
In 1955 sexologist John Money introduced the confusion we’re running into today. Before his work it was uncommon at best for the word gender to refer to biological sex. Moneys usage of the word gender as interchangeable with sex didn’t catch on until the 1970s, when feminists in academia embraced his text book Man & Woman, Boy & Girl. With academias acceptance of this usage of the word gender it was only a matter of time before it would cause confusion relating to biological sex.