[servo1969]

What defines gender?

If you were born with a penis and testicles you’re a boy.
If you were born with a vagina and ovaries you’re a girl.

Seriously, we figured this out ages ago.
It’s how we all got here.

[Ingtar]

And if you were born with both, then you have an issue to resolve. It happens. Rarely, but it does.

[pfflier]

Don’t forget the X and Y chromosones. They determine gender.