First, according to biologists, there are at least six combinations of sex chromosomes which are viable in humans. There are also xxy, xxxy, xxxy and xyy, all of which have some male expression, but with varying levels of testosterone. There are also women who have only a single x chromosome, who have lower levels of female characteristics.
Some close minded folks also say it all is based on genitalia – someone with a penis is male and someone with a vagina is female, end of story. Again, it isn’t quite that simple. First some folks are born intersex, some with both sets of genitalia, and others with ambiguous genitalia. If someone has both a penis and vagina, are they male or female?
In addition, one’s genitalia don’t always match one’s sex chromosomes. There are xy individuals who are born with a vagina, and xx who are born with a penis. It all has to do with hormonal influences in the womb, but clearly when the chromosomes don’t match the genitalia that one was born with it is not a simple one thing or another.
Another study seemed to show that there were two testosterone surges in vitro that determine genital expression, as well as gender identification and even sexual attraction. Individuals who are xy and don’t get both surges may be have a vagina or be gay or transgender. Individuals who are xx and do get the testosterone surges may have a penis or be lesbian or transgender.
Human biology with respect to gender is far more complicated that the close minded biological determinalists seem to think. Beyond that, gender outside humans is far from the simple male female binary that some think it is. Some species change genders during their lifetime due to various factors, including temperature, age, and the number of members of each gender present.
I saw one person who said we can’t have transgender people in the military because they are more prone to suicide and emotional problems. This completely ignores that fact that the higher rates of suicide and emotional problems are largely due to people like him denying the gender of those transgender people, as well as misgendering them, telling them they are sick or misguided, and often bullying them. All those things contribute to both a higher rate of suicide and higher rates of emotional problems. They are the product of societal influences on transgender people, not something inherent in being transgender.
At one point, gender dysphoria was categorized as a type of mental illness. Psychology changes as we learn more about the mind. Hysteria in women was considered a mental illness. Drapetomania was thought a mental illness in slaves causing them irrationally to want to be free. At one point, doctors performed frontal lobotomies on people to “cure” them of mental disorders. They also did electroshock “therapy” for depression and other issues. As science has progressed, so has our understanding and definition of what constitutes mental illness. Freud thought penis envy and Oedipus complex were real psychiatric disorders.
Transgender people just want to be themselves, to be who they know they are, and to live free of discrimination, free of bullying, and free of fear.