So the above links got me thinking, what exactly forms ones sexuality/orientation?
Reported for forum change.
As I understand it: Identical twins have a higher correlation of sexuality than fraternal twins, and biological siblings have a greater correlation than adopted siblings, which implies that there’s a nonzero component from genetics.
Fraternal twins have a higher correlation than non-twin siblings, which implies that there’s a nonzero component from the uterine environment (presumably prenatal hormone exposure of some sort).
Biological siblings raised together have a higher correlation than siblings adopted into different families, and adopted siblings have a higher correlation than random general-population individuals, which implies that there’s a nonzero component from post-birth environmental factors.
Last I heard, the jury was still out on the relative strengths of these three factors, beyond the fact that they’re all nonzero. But research should be getting easier with time, as the social stigma fades away and people become more willing to answer surveys honestly.