While I’m open to the possibility that there might be a genetic disposition towards this, and I’m open to science; my hypothesis is that this has a primarily environmental source.
I think there are certain things that family (and today friends) can do when we are young that can greatly screw up a child’s development.
A large number of transgender people have reported situations which not be considered healthy living conditions. For example: one transgender man I’ve heard talk mentioned that his grandmother would often tell him that she wished he was a girl. Others report their parents having better relationships or seem to favor the children of the opposite sex. Others report not having a healthy relationship with their fathers, etc.
I strongly believe the increase in divorce and Borge parents working have potentially played a role in the increase of this, homosexuality, and of mental disorders.
Finally, I also question if the birth control pill may be having a negative impact on our younger generations, perhaps being a reason for not just an increase in transgenderness, but also homosexuality, violence, food allergies, etc
Regardless, while some might have a biological source, I strongly feel that most cases have an environmental source.
God Bless