One reason is because your chromosomes donβt control genital development, your hormones do. So if youβre born with XY chromosomes and your testosterone receptors donβt work then youβll develop female genitals and a generally female physiology (minus reproductive organs).
This is all separate from gender expression obviously, but things are hard because the world is complex. If you havenβt seen or experienced this complexity in your life, thatβs fine. But donβt diminish the complexity of otherβs experiences just because they donβt match your own.
I personally know someone like that. She's currently raising a kid she gave birth to thanks to a donated egg and IVF. Chromosomes are useful for first order approximations, but biology is a glorious fucking mess that cares not for simple binaries.
I hope that the person you're responding to will be able to form a new opinion after seeing these very measured and thoughtful responses. I'm really pleased with how calmly the community is handling this particular comment.
As a general rule, when it comes to any science, the version you learn in grade school is extremely simplified to the point of being almost entirely useless. To draw a parallel to physics, if you ask a physicist "how many states of matter are there?", they'd probably consider it a difficult and poorly defined question, the exact distinction between a distinct state and a subset/variant of a state is up for discussion, but any coherent model has at least 20 states. What you're saying is the equivalent of "what's so hard about solid, liquid and gas?"
Can somebody please enlighten me with some numbers on the commonality of said deviations. I always assumed they made up such a small percentage it wasnt relevent same as people with 4 or 6 fingers.
How big does a minority need to be before it's "relevant" enough to be acknowledged and its members' rights respected? People with 4 or 6 fingers exist. People whose chromosomes don't match their physiology exist. People whose gender identity doesn't match their genitals exist. It doesn't matter how many of them there are, because every single one of us is a unique minority of one.
But you asked for numbers, so I'll give you some numbers.
According to this article, around 1.7% of people are intersex, meaning they have physiology that doesn't fit neatly into the common conceptions of male or female. That's close to the number of people with red hair, which is estimated to be 2% of the world population. I have never heard anyone suggest that redheads are too small a percentage to matter.
I think you were asking specifically about chromosomes, though. There's a table in the linked article that breaks down intersex conditions by cause. The first entry is "Non-XX or non-XY (except Turnerβs or Klinefelterβs)". This refers to people with XY chromosomes whose bodies developed female characteristics (Swyer syndrome) and people with XX chromosomes whose bodies developed male characteristics (de la Chapelle syndrome). It does not include people with X, XXY, or XO chromosomes. (Those are the next two entries in the table.)
The estimated frequency for this condition is 0.0639 per 100 live births, equivalent to 0.0639% of population. That looks like a really low number, right? Surely not enough to be "relevant"! Except... There are 8.1 billion people on this planet. 0.0639% of 8.1 billion is 5,175,900 people, which is roughly the current population of New Zealand.
Remember, that is only women with XY chromosomes and men with XX chromosomes. If we include all intersex people that number rises to 140 million, which is nearly the population of Russia.