This may sound like I'm backtracking a bit, but it isn't, I'm just letting the discussion develop, like a good discussion should
I do think that there are perhaps a greater number of bi-sexual people, or people who are sexually hedonistic where the sexual urge outweighs a sexual preference, than we actually realise.
Let's simplify this... I like curvy women. I don't know why I have that preference, but I do. I have no preference over hair colour, height, etc. I probably have a "face type" too, but I've never really studied it.
However, I've slept with women with a wide range of body shapes. The way my natural "attraction" favours doesn't determine if I'm going to sleep with a girl or not. It's all down to environmental factors. It may be we hit it off mentally, I may just have a case of full sack and need release or she may be naked in front of me and who can refuse eh?
The point is, I can over-ride a personal preference in favour of sexual gratification. The only thing I do require is that they're female. I suspect a number of people don't actually stop at this last point. As long as there's sexual gratification then that's the goal and how it's achieved is irrelevant.
It's all about what is more important to you as a person. I still believe it's something hormonal/genetic/chemical/biological but it's there. Here is where society makes a big difference.
If you're sexually uninhibited, then you will always go for the "easiest lay". As was mentioned by Ben, in a Muslim country you're unlikely to go the homosexual route as it's tougher socially than a heterosexual route. As has been the case I suspect in many cultures for hundreds of years.
This is a point I've always agreed with. Those who are gay, are gay. Those who are straight, are straight. Those who just want sex go with the flow. If you're one of those brought up in a relationship with two gay parents, then you're most likely to find the flow is easiest to go gay. Socially, this is a fantastically flexible attitude. The point is, the likelihood of you going one way or the other, or whichever way you feel is already there before the social environment makes the change.
Oh, and I don't think my hatred of Marmite is genetic, but it's certainly something biological or chemical. My taste buds react negatively to Marmite. While my taste buds have changed and matured and developed to a degree over the years, they still react negatively. Some things you just don't like because there's something built in your body that doesn't like it. I'll agree my hatred of ketchup is psychological, I recognise it as such, but my hatred of Marmite is purely one of my taste buds telling me that it's not good.
Mark/Marc - I mentioned very early on that (I assumed) a lot of people "know" which way they are aligned at an early age. I think it's interesting that some people strongly know so early and others don't. I think it's probably all linked somewhere, but we're well into the realms of experts already :lol: