Its not about DNA, its a state of mind. There is no link between DNA and what people perceive as gender. It has nothing to do with physiology/biology, it has everything to do with psychology, sociology, etc.
For example, Black people and White people are pretty much the same. Asians too. As far as DNA goes they are 99.999999999% identical. I might have more in common genetically with a Black or an Asian than I do with another White person. But look how different the cultures are... its all just social construction.
Gender has EVERYTHING to do with your body and theyparts you have....it has nothing at all to do with anything else. The parts you have are what make you a male or female (sometimes both) but you cant change that by surgery or simply thinking you are something else.
How would social construction change body parts? That makes no sense whatsoever.
Thats beyond me LOL I have no idea. If they were born with male parts they are a male or if they were born with female parts they are female I know that much.
My beliefs are my beliefs. You can believe that someone can think about being another gender so hard that something happens and changes their body all you want. Thats your opinion.
Their body doesn't change genetically/biologically. What changes is their legal status and the social and cultural recognition of their gender. You accept them as what they say they are regardless of parts they may or may not have.
Here's a question for you, what makes you a man... is it just biology, or is it not also culture? What would you say if you went and had a blood test and they told you have 2 X chromosomes (female) instead of XY (male). Would you still think of yourself as a man, or would you start dressing and acting like a woman?