“Being Transgender is a fact of nature;………..a mismatch between gender identity and biological sex is not something people choose. The most common description given by transgendered individuals is a persistent, painfully distressing belief that they are females trapped in a male body, or vice versa.”  from a column by Jane Brody, respected personal health journalist.

See http://well.blogs.nytimes.com/2016/06/13/transsexualism-as-a-fact-of-nature/?_r=o

She writes:  “Those who insist that people should use only the facilities that match the sex on their birth certificates may not realize that most states allow those who change their sexual assignment to change the sex on their birth certificates. Furthermore, a transgender individual using a facility matched to his or her gender identity is no more of a sexual threat to others than anyone else using that bathroom might be. Psychosocial distress or embarrassment can be avoided simply by providing closed-door toilet and changing areas in public bathrooms and locker rooms. After all, we should be used to mixed-gender bathrooms by now: We’ve had them in our homes for years.”