Re determination of human sexual orientation what does the latest science say re nature/nurture?

Well, I guess we disagree on what constitutes “very different results”. The distribution in that cite shows that a strong majority of younger adults (64%) report being completely heterosexual whereas an even stronger majority (78%) of all adults do. If you add up the 0 - 2 category, let’s call that “leans heterosexual”, then it comes to 88% of the total sample of adults compared to 83% of the sample of younger adults. Now, let’s throw in the error margin of the sub-group (I don’t know what it is, but as a sub-group, the results for the 18 to 29s will have to have a bigger error margin than for the whole sample), that will throw in even less confidence in the supposed difference.

Now there is the bit about the numbers of people identifying as bisexual or homosexual, if that’s what you’re referring to - and it is curious that those bullet points don’t quite match up with the distribution of the Kinsey sexuality scale.

But be that as it may, my observation was - and remains - that saying there is a spectrum of sexuality glosses over the fact that the strong majority of adults, no matter what the age, place themselves in the absolute category of heterosexuality.

Again - I have no agenda.

Huh? I’ve not made it a mission to find out, but… I consider myself well read, and in all my meanderings through various writings - have yet to see a cite that suggests that homosexuality is a heritable condition, based on scientific evidence. (I’m betting people with agendas have tried to find the link; and if proven or even strongly suggested, it would be front page news for some corners of society) Hence “…I don’t see any evidence…”

the short answer is - we don’t know why it happens.

I think you’re kind of cherry picking to avoid the main point: what people say on a survey clearly depends on their culture-- even in the same country, just by changing the age of who you ask, you get a 14% difference.

Given that we see such a big difference among people from the same place, and only a half-generation apart, what kind of difference do you think we’d see between a generation born in 1990 and one born in 1790, or 90 BC? And between middle-class U.S. and, peasant farmers in Guatemala today, or the ruling class of ancient Sparta or Julius Caesar’s contemporaries? Are you sure that all of them would even understand what ‘exclusively heterosexual’ means? [Check out what info we have on the sexuality of Spartan hoplites or old Julius himself].

Look, my best guess is that the majority of humans do have some kind of hard-wired attraction to the opposite sex, and the majority of those that don’t have some kind of hard-wired attraction to the same sex. But I also know that it’s hard to understand that other cultures have different underlying assumptions that we do, and can occasionally underestimate the differences, and I am very very sure that human beings are very very complicated things that conceptualize and act on vague hard-wired impulses in very very different ways depending on their social situation.

And I know that people lie about sex.

So I’m just saying if a self-reported survey gives a huge difference between adjacent generations in the same time and place, it’s not a very good tool to tell us much about actual unchanging human physiology.

Quercus, you raise reasonable points, of course, but you’re going quite a bit farther than I ever argued. My sole point was to apply some nuance to the idea that sexual orientation is a spectrum.

If the question is: is sexual preference a binary or a spectrum? Well, it’s strictly speaking a spectrum, because people do fit in a range of preferences from exclusively heterosexual to exclusively homosexual. But the reality is that a majority (whether it’s 50%, 60%, or 70% doesn’t matter) say they are exclusively heterosexual, which isn’t really spectrumish. It is thoroughly cromulent to look at those data and say “Most American adults say they are completely heterosexual, but there are different degrees of interest in the same sex among those who are not”. It’s not at all like colour, height, politics, IQ, etc.

Of course when you change the question, ask it of different ages or cultures, you get different answers. Yes, people lie, too. But all I’m saying is I think the degree to which sexual orientation is a spectrum is overstated.

And as to whether the difference is “big” or not - well, we both agree that it’s 14% between younger adults and the entire population. With the error margin, I wouldn’t call that big, but it’s a glass half full/half empty argument.

And dude, I’m not cherry picking. I’m looking at a whole dataset in its entirety.

Leviticus suggests that even 3000 years ago some societies had the same negative attitude toward homosexual behavior (by men). They simply relied on direct evidence of behavior rather than “expressed preference” as the grounds for discrimination or imposing punishment. Even in European cultures, punishment for sodomy predates the 19th century by quite a bit.

It’s almost like the joke about “I built that bridge, but do they call me Bob the Bridge-Builder? No…” The social view is that if the male expressed any interest in other males at any time, he was stigmatized as “homosexual” no matter where on the spectrum he was. But then, this was the same test Leviticus applied 3000 years ago.

So it’s a spectrum with a strong spectral line at “heterosexual”.

How are you defining “spectrum”?

For example, about 70% of younger adult males in the United States (aged 18-44) are between 5’6" and 6’, but the overall spread ranges from sub-4’ to 7-foot plus–in other words, a strong majority are in one particular and fairly narrow band. How is that “not at all like” sexual preference?

Which is a perfectly sensible position to hold. What you wrote though, read exactly like what a person concluding from two personal anecdotes would write.

A spectrum is generally defined as a representation of a continuous distribution, and D18 is likely correct in saying that for a majority of the population, sexuality, especially as it pertains to being attracted to the opposite sex, is not a spectrum, but a discrete binary. I don’t have a degree of interest in the same sex as me, I have none, and that’s likely true for most of humanity.

That doesn’t make having interest in the same sex wrong or unnatural, it just means that sexuality (again, as it pertains to being interested in the same sex) is a spectrum only for those who have some interest in the same sex, and that is a minority of people.

No, sexuality is a spectrum because there exists a range of attraction to same, opposite or a combination of sexes. Saying sex is a spectrum only for those who have some interest in the same sex is like saying colour isn’t a spectrum unless you like more than one colour.

Interesting discussion! I hope astro doesn’t think this turned into a hijack, but is an organic extension of his question.

Chronos - good one!

slash2K - there’s a huge difference in the distributions of the Kinsey scale and height. Height is a spectrum because you have a continuous variation, and presumably if we could measure it accurately enough, no two human beings would be the same. With height you also don’t have any sort of self/other opposition. The shortest person in the world simply has fewer of the same types of cells as the tallest person in the world; they aren’t made of different stuff. In addition, there isn’t a single height that predominates to the same degree as “completely heterosexual” does in the Kinsey scale. Sure, there is a mode for height (assuming we collapse everyone to the nearest inch or half inch), but as I say, measure everyone accurately enough and no two people have the same height.

Sexual attraction on the other hand there is a viable binary opposition that we can model. A majority of American adults report having no same-sex tendencies; so the same-sex switch is turned off; a minority report the same-sex switch is turned on. Now, if you want to say it’s closer to a rheostat than a light switch, you’re right of course, but that doesn’t accurately describe what’s going on.

Or what bldysabba said!

naita, you conflated whether colour is a spectrum with whether there is a spectrum of people’s attraction to specific colours. The distribution of people’s interest in the same sex looks nothing like the distribution of the colour spectrum, which is why I think it is inaccurate to describe sexual attraction as a spectrum.

boldng mine -

Do you mean inheritable as in traits ? (recessive vs dominint, like hair/eye color, etc)

Because I would agree - nothing that I have seen suggests it is inherited in that fashion. What I have seen/read is that there is atleast some evidence that it may be linked to hormone levels in the womb - which makes it a trait that that specific person ‘inherits’ but not in the way that term is usually meant.

I also am in the camp that our sexuality changes as we age/allow it to - so while there are some factors outside of our control (‘born this way’) - for some, it is a full spectrum that may change/evolve/change back again as one experiences life.

I do not believe its ‘binary’ and the ‘binary’ nature that many want to think it is seems to be the part that is imposed on by cultural attitudes.

Actually, on thinking about it, I’m not so sure that completely heterosexual people actually do make up a majority. I’ve seen a number of comments on this board, and heard them in real life, to the effect of “I’m not gay, but <insert name of same-sex celebrity> still tempts me”. Even taking all of those folks at their word that they’re significantly closer to the straight end of the spectrum than the gay end, they’re still not completely heterosexual. And when you take all of the people who say things like that, and add in the number who think things like that but who don’t say it for various reasons, I wouldn’t be at all surprised if they outnumbered the complete heterosexuals.

Come on, Chronos, you know the difference between a well-worn joke and data! :wink:

That’s a reasonable hypothesis of course, but until there’s a study to support it, there’s no study to support it.

That’s ridiculous. Height is something which is ultimately fixed and varies little (except for illness, injury and eventually old age) from person to person. You don’t decide to be tall one day and short the next, you OTH can have sex with either or both same and opposite sex people whenever you choose.
Self-reporting is always suspect and especially on the issue of sexuality. I can easily self-report myself as pretty much anything in such a survey, and you have to account for the ashamed/bashful as well as the boastful, which in a self-reported survey is not going to be easy to eliminate or even reduce, hell even identify.

^Too late to edit. I’d like to change my second sentence to read: is there any data that support the spectrum model of sexual attraction more viably than the Kinsey scale distributions I linked to? I’d be genuinely curious to see it.

You can decide to have sex with a man one day and with a woman the next, but you can’t decide to be gay one day and straight the next. Try this: Can you decide to have an erection? Most men can’t… but it just happens on its own, when you’re exposed to certain stimuli. And which stimuli those are varies from man to man, and changes (if at all) only very slowly.

Yes, you can very easily change how you answer a survey question, but how you answer a survey question is not your sexual orientation. The fact that they’re different makes it very difficult to measure orientation, but it doesn’t mean that orientation doesn’t exist.

Having most of the data points clustered at one end doesn’t mean something is not a spectrum. Incomes are a spectrum, even though the vast majority of them are at one end of the graph.

It just means you don’t have a normal distribution.

Actually, a normal distribution could be fairly called a spectrum, too. What most people mean by the term is just that it’s non-binary.

It’s not just that most of the data points are clustered at one end, it’s also that most of the data points are “completely heterosexual”, which is an absolute. So you can set up a binary model that says code 0 for no same-sex attraction and 1 for any same-sex attraction, and have a defensible interpretation of what the data says is going on. And in my opinion, a more accurate interpretation of what’s going on than saying it’s a spectrum.