“Speaking of gayness... I’m not sure where ...”
I’m curious because it hasn’t been resolved by our scientists whether gayness is in the DNA or is acquired.
It occurs to me that left-handedness might also be a characteristic whose origin in a person is unknown.
Maybe there are many characteristics of people whose origin is unknown. I’ve given this a limited amount of thought.
There have been studies that find a few "bits" of DNA (the the midst of millions of bits) which seem to be orientation markers, but even that's just correlation: there's no sign of actual causation.
This article discusses the latest speculation.
Therefore there seems to be more attention paid now to intrauterine influence including maternal hormones and endocrine disruptors such as phytoestrogens, disrupted early childhood socialization, and damaging childhood experiences such as sexual abuse.
Even there, they're looking at factors that influence sexual orientation. That's quite different from determining it.