I don’t know, I think that there might be people who are born gay, not all, but some.
There are a disproportionate number of gays born into some families, like my husband’s family, on both his mother’s and father’s side. His one uncle had three gay children, two guys and a girl. The oldest one tried to deny it and married into a very prominent WA DC family, only to disgrace himself, his law firm and the family when he got caught in some homosexual situation. I went to that uncle’s funeral and the kids stood up and spoke about their father and how they loved him but didn’t like him because he could never accept their homosexuality. Well, it might have been easier to accept if the first one had foregone the society wedding and the subsequent scandal.
There are also numerous other gay cousins, but no evidence of homosexuality in the parents as far as I can see.
Propensity of a family can just as easily be attributed to environment as nature. Perhaps all 3 were molested by that gay uncle as youths leading them down a path toward homosexuality.
So I guess by your anecdotal evidence. The Italian’s have a Mob gene, because so many have become Mobsters, at least in the past.
Just curious, maybe it doesn’t correlate.