[quote]
Right, its a bit like asking how many shades of blue there are.
[/quote]
This is basically a perfect summation of it. 

But I will humour this.
[quote=@SleepingSilence]
That is not how the world works. If we're going to change how we were using the word as we have been. The two genders correlate with the two sexes strictly. And we're going to alter our laws we cannot have an unknown amount of genders and gender pronouns and then expect to jail people who misgender someone for hate speech. 
[/quote]
Are you sure about that? 
Looking through Google Ngram Viewer it would appear the earliest citable use of the word "gender" is in 1718
https://www.google.ca/search?q=%22gender%22&tbm=bks&tbs=cdr:1,cd_min:1500,cd_max:1779&lr=lang_en&gws_rd=cr&dcr=0&ei=ZDaXWpiUMomUjwTqpoawDQ
Even back then gender did not refer to the biological differences between man and woman. It referred to what you would use to conjugate words in a sentence: he, she, it. Of languages I know french and russian there is masculine plural and feminine plural in addition to the English styled neuter plural.

From the 1950s or so, it started to be used in context of people feeling neither male nor female pronouns describing them. 

[quote]Actually while I'm down this road. Changing the law to justify people's fantasies, without even a shred of skepticism. That means I'd assume you'd support giving puberty blockers to 3 year olds, punishing parents for child abuse if they don't give them hormones. Letting every human being on Earth use the bathroom that they choose and changing room for that matter.  Because gender is a social construct and every single human being on Earth can be gender-fluid. Even questioning it would be transphobic. The government/others would have to completely change every single documentation, book and school policy. Things like grants for new businesses for women could be completely taken by men who transition. And male to female boxers like Fallon Fox can beat the ever-living shit out of women. We can leave the startling suicide rate statistics completely by the wayside along with common sense and biology. I assume you support all of that since you're using that particular "people think it's so it must be true" logic. Is trans race and trans age a social construct thing to?

You are not doing anyone favors by pretending there are more than 2 genders.
[/quote]

Oh don't get me wrong. I'm 100% sure transgenderism is a mental illness and as with most other mental illnesses you should not indulge the delusions of the insane, in all but the most dire cases, particularly since many people "grow out of" transgenderism, whilst you can't grow out of slicing off your tits. I am wholly against hormone blockers and enforcing gender confusion amongst children. But arguing over linguistics will only waste time while parents are slicing off their kid's weiners against their will, and will detract from the problem of actually helping these sick people with their problems.