Why might lgbtq rights groups be predisposed to believe that homosexuality has a genetic origin?

LGBT rights groups be predisposed to believe that homosexuality has a genetic origin because if sexual orientation is something one is born with, then discrimination is much less acceptable.

Research results show that those who believe sexual orientation is inborn are more likely to have tolerant attitudes toward gay men and lesbians, whereas those who believe it is a choice have less tolerant attitudes.