I'm a non-identical twin (dmab), now identifying as bigender. My sister is cisgender female. I've heard a theory about hormones in the womb being the reason some people are transgender. I figured that if that is the case, non-identical twins might be more likely to get an unusual balance of hormones in the womb and therefore more likely to be transgender. This is completely speculation as I don't really understand the science behind the theory - just wondered if anyone had any thoughts on the idea.
I've heard of two different sets of monozygotic twins where one was cis and the other was trans. Could be to do with hormones, I know it's a factor for sexuality so could be for gender as well. There are some males who are born without their penis, but gets it at age 12 because at age 12 they don't need a type of hormone to grow the penis which is needed at birth.
Fellow non-identical multiple here; all my siblings are (to my knowledge) cisgender/straight, and I ended up both gay and trans I also don't understand the science behind it but, I always kind of wondered if I somehow didn't get enough testosterone to develop physically as a male.... yet still got enough to develop that way mentally? That may not be how it works but it's something I've wondered. Interesting to know there's a theory about it.
Always wondered if birth order affected anything. Oldest sibling is a (probably) straight cis male. I'm a bi trans male. All my younger siblings (different biological father) are girls (although who knows if they'll be LGBT as they get older? The oldest is 12, youngest is 6).
My sister and I are fraternal twins. My parents and relatives tell us all the time that till our adolescence my sister was more of a tomboy and I showed feminine traits in mannerisms and thought processes (read stereotypes). So I believe it is possible
