I am a passable, binary, transgender female, who has undergone GCS, is taking HRT, and has done a number of other procedures to make me indistinguishable from a cis woman. My mother had one sister, who was almost certainly a lesbian. She never married, and never had any romantic partners of which we were aware. She held a PhD in physical education, was masculine in dress, bearing and demeanor, and an athletic director for a woman’s liberal arts college. I also had an uncle who never married, who was definitely gay. My youngest of two brothers is gay and married to his husband.
At a bare minimum there seems to be a genetic component to sexuality and identity in my biological family on my mother’s side. When I was younger, I would’ve considered myself a firmly heterosexual male. I had absolutely no interest in men. However, I was frequently propositioned by men who would often refer to my “bedroom eyes“. As a teenager, I had no idea what they were talking about.
For much of my life, I was heavily involved with evangelical Christianity. I held no antipathy towards gay people, but for a long time I thought they were confused and could get their life together if they worked on it. That was before I realized that being gay, like being trans, was innate and not learned behavior.
I am confident that being trans or gay has a genetic (and possibly in utero developmental) component. In my case at least, my upbringing and environment would have conditioned me to distance myself from the LGBTQ community and to have held them in contempt (like many modern-day fundamentalists) if it were a developmental factor. But here I am, a happy trans woman who is now attracted to guys as well as women. My environment had no effect upon my evolution. Quite the contrary. I am the woman I am today in spite of my upbringing.