@Anglican which is what gender is

being born with six fingers has nothing to do with the chromosomes that determine ones sex

intersex is a combination of sex chromosomes that contradicts the sex binary

it isn't just XX vs XY

thats isn't what intersex is

It could also be one less chromosome

regardless their existence contradicts the binary

a binary is composed of 2 mutually exhaustive and independent categories

the fact that there are more than 2 categories, means that sex isn't a binary

it doesn't matter that there isn't a "Z"

sex is determined by combinations of chromosomes

You're not making any sense

does biological functionality define our concept of sex?

You're making a value claim

that has nothing to do with the sex binary

I agree that humans would go exstinct if everyone was intersex, but that has nothing to do with my point

sex isn't an ideal state of affairs

its an existing state of affairs

as for functionality, intersex people can be fertile in some cases

that have functional sexual organs

it isn't subjective

sex refers to a combination of chromosomes

can they have both functional organs tho

it isn't tied to genitals

sex isn't defined by genitalia

you're changing your argument

yeah because you're clearly biased from some reason

yeah thats the point

http://www.who.int/genomics/gender/en/index1.html

Well I don't think any of the definitions result in a binary. If something is somewhere between a penis and vagina it isn't really either.

what would you classify it as?

a third sexual category, would be definition

seeing as it doesn't fit the binary

you're really dodging the issue with your definition

calling it a birth defect, or stating that their genitalia are dysfunctional has nothing to do with the implications on the sex binary

it isn't subjective

mine is the scientific definition

confirmed by the sources you provided

well thats a whole different issue

and again scientifically speaking, gender is distinct from sex

sex and gender aren'y synonyms