Interesting read. Thanks for posting this, SophieD!
Polling/statistical analysis on sexual orientation and gender is tough, because you can never be sure you're getting reliable data. We all know that LGBT populations are strongly under-estimated because of lingering social stigma, with trans folks being the most stigmatized, and hence the most "hidden."
The accuracy and reliability of polling are also suspect because of the slipperiness of the categories involved. Here's an example from the Pew analysis that SophieD linked:
"In Pew Research Center's 2013 survey of LGBT Americans, 40% of respondents said they were bisexual, while 36% identified as gay men, 19% as lesbians and 5% as transgender."
Very nice! 40% + 36% + 19% + 5% = 100%. So Pew has accounted for everybody, right? Wrong!
For simplicity, Pew has broken down LGBT people into four mutually exclusive categories and asked respondents to sort themselves into one bucket or another, to the exclusion of the others. That isn't how people live their lives. And still less how people live their sex lives.
Let me give you an example: me. I'm an MTF transwoman. When I was a teenager, everyone just assumed I was a gay boy. (That's what I thought, too!) It took me a few years to sort through my feelings and identify the fundamental gender identity issue that set me on the path to transition.
I have always been sexually attracted to and active with male partners. But as Andrew (the old me) faded and April emerged, I've discovered I am more and more sexually attracted to women as well.
So if I had been interviewed as a teenager by Pew, they would have classified me as a gay man. If I had been interviewed a little later, they would classify me as transgender.
But that's not right, either. It's too simple. As a teenager, my orientation was "gay," because it was directed towards other males. As my transfemale identity emerged, the object of my attraction (i.e., men) remained the same. But as I subjectively expressed more and more as a woman, my orientation shifted from "gay" to "straight." Weird, huh?
But that's not the end of it. Because as I gradually came to recognize my growing attraction to women, my sexual orientation is evolving to bisexual. I guess the best description of me now is a bisexual transwoman.
For the sake of analysis, Pew would pigeonhole me in the 5% of the LGBT population that is "trans." But really, I've been all over Pew's map in the course of the last twenty years. All of us are a lot more complicated than Pew understands. Even though I've been all over Pew's theoretical landscape (with the exception that I've never identified as completely lesbian), I've always been the same person: me.
Even with the theoretical limitations of studies like Pew publishes, I'm still glad to see them. They make a very important point. We're not alone. There are, in fact, MILLIONS of us.