Well, since the brain isn't fully formed until the teen years, I'd be willing to say that it's 85 percent biological at birth, with the remaining 15 percent being the environment the child grows up in.
But, the 15 percent won't override the 85 percent, which is why you have people coming out of the closet after marriage.
I don't know about that random 85/15 split. I'm sure there is some genetic predisposition to homosexuality that's more or less determined at birth, but I don't think we really know the extent to which environmental factors play a part in developing one's sexuality. I don't think it's mostly any one thing
I'm sure witnessing the relationship between my parents played a big part in it. Seeing how men and women interact with one another in our society I'm sure had something to do with it. The relationship I had with my mother. The relationship I had with my father. My interactions with various and sundry people, male and female, throughout my life, has influenced my orientation. I can't say I ever contemplated liking males.
First of all, that wasn't the argument they used. They said the law wasn't racial discrimination since it pertained to both blacks and whites. That argument didn't work, for one, because it was plainly incorrect. The Racial Integrity Act precluded whites and nonwhites from marrying, not any type of interracial marriage two people could formulate. But it also failed because it ran afoul of the spirit of the 14th amendment, which was to do away with laws denying blacks of certain rights simply because of their race. The entire notion of race-based laws is more or less unconstitutional, up to and including marriage restrictions.
But that's all academic. The real point is, it doesn't matter. Just because an argument doesn't work in one case doesn't make the argument invalid altogether.
Your "man/woman" argument isn't going to stand up to the constitution anymore than theirs did.
There is no societal harm in allowing gays and lesbians to marry. The SCOTUS will have no choice but to rule in favor of gay masriage.
I wouldn't be so sure about that. All these marriage amendments do is define marriage. They don't criminalize and punish people, i.e. by promising jail time or fines, just because someone's relationship lies outside of what's the norm.