Your post is gibberish. Subgroups? Demographics and culture? Pure psychobabble. It was a study based on the mental illness called homosexuality and their tendency toward violence. I have a brother that’s “gay”. I used to “gay” bar hop with him and his friends. And they ARE violent. And unstable.
My cousin is gay and lives with his partner, and I agree with you to a point. The violence is often manifest from self-loathing. In my cousin's case, he was a closet homo for most of his youth, and he tried to take his life several times before he finally came out and everyone in our family accepted him as-is. His despondency never went away, it just migrated to a new subject: his partners.
I would bet that many guys aren't proud of what they're doing, but as the social experiment of liberalism continues to grip our country, it will grow to be socially acceptable, and this sort of behavior will likely wane.
Sad really. Violence against another of the same gender, regardless of relationship, is really hardwired in us. Women keep away other women to ensure they have exclusive access to the male's breeding and relational benefits while men fight other men for dominance and show. Two men or two women being together in a relationship is completely counter to natural order, IMHO.