Contention 1: Homosexuality is entirely innate, ergo it should be morally/socially acceptable.
This one is quite simple to refute, really. No scientific data or evidences can conclusively support this proposition. In fact Simon LeVay himself once said he did not want anybody to misunderstand his work in the way in which they would construe it as proof for the innateness of homosexuality[1a]. Many scientific studies will indeed claim as a thesis that indubitable proof has been recognized, but oddly enough these studies always seem to conclude on the same equivocal note[1b]. Saying that 'the evidence suggests(note) that biology may(note) play role(note) as predisposition(note)'. Let us analyze this hypothetical illation(I will post a link at the end of this contention to prove my point[1c]). The first word I noted was 'suggests'. All this word really claims is that the evidence concludes that 'it might', or that there is a reasonable possibility in terms of the validity of truth of the statement that follows the word('suggests'). The next word is 'may'. Same thing with this word as with before. The next word is 'role'. This word indicates that the biology is a constituent of homosexuality, rather than a causal disposition. We must also herein understand that when advocates claim that 'biology plays a 'major' role' they are using the term(major) relatively. Before homosexuality was biologically deliberated, it was thought that it was solely the result of psychological dysfunction. So now after the predisposition has been essentially proven, the conclude the course of events with the inference that biology plays a 'major' role. It should be clear how they are using the term major here, not as in more than 50% causality, but simply more than previously thought prior to scientific investigation. The final and most important word noted is 'predisposition'. This concept should be put under scrutiny being that most all scientifically qualified persons(even the majority of gay rights advocates) do chose the espousal of this word when referring to the biology(do note: when I use the term 'biology', I am referring to genetics/heredity, as well as endocrine intrauterine(prenatal) environments) of homosexuality. This basically says that all of the biological factors lead up to an implicit causality rather than an immediate one. http://www.narth.com...[1abc]
The fact of the matter is that homosexuality just isn't an inborn characteristic, nor is it an 'integral part of a person'. It is simply an askew sexual development(this is not necessarily a bad thing, as I will show hereinafter) that is confirmed and supported by a society that blindly looks to accept anything that tends toward the proclivities related to love.
There is no conclusive data that can support that homosexuality is entirely or even partially innate. This being said, the logic that it should be accepted based on it being innate is faulty. And moreover innateness shouldn't dictate its acceptance anyway. Serial killers are known to be disposed to killing via a conglomeration of direct and innate dispositions. This does not make it anymore moral for them.
The idea of biological predisposition being fulfilled by psychological environment works infinitely better than the archetype of it being solely inborn. This is because, for example, heterosexual attraction(which is psychological, as it is a preference) is built off of the innate instinct to reproduce with the opposite sex. It is only logical that homosexuality would follow this archetype. Subject's innate instinct to reproduce is shifted via psychological dysfunction, and then on the attraction builds from there