What makes people gay, straight, lesbian or bi?

I believe your born with it, trust me no one wants to grow up being sexually different. You grow up having that attraction towards boy/girl, simply because its in your blood. Its not a problem, and i hope that one day its completely accepted.

They're on the right track baby

You look at someone and see if you are sexually attracted to them. I mean, I don't know how it could work another way.

Probably a mixture of biology, psychology and social environment. Though science isn't really at the level to determine exactly what makes people gay or straight. Though I suspect there most be some social influences, as some cultures don't have homosexuality in the same way the modern west typically sees it. The idea of sexual orientations themselves are probably partly socially constructed. "Gay", "straight", "lesbian" or "bi" are simply social sexual identities which people place on themselves and others.

My guess would be that people are just born that way.

Though, taking the whole separated identical twin thing into consideration does open up possibilities for it partially relying on outside factors. It doesn't open up too big of a window, though. I mean, there are variations in DNA, even in identical twins- they're just minor.
I think it would be a much more sound argument if we saw more homosexuality in certain cultures and whatnot (still not very good, but decent)

... or, maybe, everyone's bisexual and preference is determined by society and all that.

Wow... I can't believe that some people still don't have a clue... If you're Straight, or LGBT, etc., you were BORN THIS WAY.

Other:

who you have sex with determines this.

If you have sex with your own gender only you're gay / lesbian.
If you have sex with the opposite gender only you're straight.
If you have sex with both you're bi
And if you have sex with anything with a post code you're Captain Jack Harkness.

I'm beautiful in my way coz' God makes no mistakes, i'm on the right track baby i was BORN THIS WAY!!! :D

as far as I know the current consensus is that it's about 50% nature (genes) and 50% nurture (external factors like upbringing etc), based on studies involving identical twins who were separated at birth.

It's both nature and environment, where the environment can effect what genes are expressed/not expressed that determines factors of *biological attraction*, as in, how does your brain respond to the traits (whether they be smell, appearance, or voice tone) of one or the other sex. It is then, in my opinion, another factor which is both genetic and environmental who you love in a romantic way. Sometimes these two things sync up with people, sometimes not.

Also, I think, as with most things, there is a certain amount of choice involved, in at least some cases. This doesn't make any choice "wrong", in fact, I view it as an even stronger support of all sexualities to say, yeah, it might be a choice, or it might be biological, but both are perfectly alright. I'm a female who generally has preferred males. Does this make me 'straight' or mostly straight? No. Because I view my sexuality in an open way, I still yet could be attracted to a female if the right one came along, romantically, sexually, or both. Even if that never happens, having a flexible sexuality to my way of thinking is a more 'natural' state for human beings, especially because it makes things more about the individuals, and less about categories--of gender or of sex.

In this way I do think it is a bit close-minded to view ones' self as straight, gay, or lesbian...but then again, I also respect people if that's how they want to think, and recognize that they might have some cultural or social reasons for wanting to strongly self-identify with a particular sexual orientation. I just find this redundant and cluttering...treating those I fall in love and/or lust with as unique, and as human beings, is what I hold more paramount.

Oftentimes people are too quick to 'pick their category' in the realm of sexual orientation anyway. Summary: it's limiting, but perfectly alright if that's what you want.

i think its the people you get involved with. how you get treated and how you accept it depends on ur sexuality

Investigated it, liked it, and stuck to it. That's my guess.

haha,yeah..i think im bi.i've been dicked.and got head from a girl

I don't think its upbringing because if that were the case I'd be straight, considering I was being conditioned to be a slave of a husband, not to mention lesbian bimothers and gay bifathers would end up with homosexual children and that is not aleays the case. Bisexuality I think is genetic and more of a way to get maximum results you know? If you're attracted to both genders you have more options.

Nature & Nurture

shit doesn't exist the best way i can put it is from tropic thunder "lance? *thinks about it, then* lance?! hey everybody's gay once in a while!"

Genes give tendencies, but it is also greatly affected by the society in which you live. All ancient Greek men were bisexual, because that's what was acceptable and normal in their society.

I have to agree with Curiouser... I think it is mostly upbringing but some genetics are also a factor.

I think that it through birth by hormones, but a positive upbringing can help you be more psychologically aware/confident in who you are.

If a boy grows up without a dad or any father figure he will conform to his mothers ideas and lifestyle. A girl growing up without a mother might do the same with her father.

(im not a homophobe, i just don't understand . . .)