[blackshoe]

Zelandakh, on 2015-June-15, 08:13, said:

So if you are going to work in this area, you better be very sure of your results before publishing. And such rigour is unusual in the social sciences.

Quote

The difference between science and the fuzzy subjects is that science requires reasoning, while those other subjects merely require scholarship. - R. A. Heinlein

[barmar]

Zelandakh, on 2015-June-15, 08:13, said:

So if you are going to work in this area, you better be very sure of your results before publishing. And such rigour is unusual in the social sciences.

Or even when researchers try to be rigorous, it's really hard to know what details are important. At the time the experiement you cited was performed, there probably hadn't been much research into how memory worked, so they had no idea that the ability to remember things was strongly biased by how familiar the objects are. The human mind is really complicated, and performing rigorous testing of it is hard.

This reminds me also of the long history of IQ tests that showed that blacks were not as intelligent as whites (and were presumably cited in "The Bell Curve"). What has since been discovered is that the IQ tests were very culturally biased. There was vocabulary that lower class test takers just didn't understand, and word problems that referred to activities that they didn't encounter in their lives. Since there was a strong correlation between race and culture (African-Americans were mostly poor and lived in inner city ghettos or rural areas, whites were more affluent and lived downtown or in suburbs).

[nige1]

helene_t, on 2015-June-10, 04:40, said:

Why don't you think it is innate?
It probably isn't 100% innate in the sense that all of us are 100% determined at birth to chose a particular sexual orientation. Some are potentially bisexual and could be swayed in either direction depending on peer pressure and which potential partners we happen to encounter. I know several homosexuals who came out of the closet at mature age, so obviously there must be some who never came out at all, and you can imagine that they might have come out at younger age if there was less social pressure against it, although I suppose it is also possible that some really change their sexual orientation along the way.
But it is my understanding that the evidence is strong that innate conditions have a substantial influence.
Your remark about overpopulation suggests that one reason why you don't believe it to be innate is because it doesn't make evolutionary sense. Actually, it doesn't make much evolutionary sense even in an overpopulated world since it will always be the genes of the best breeders that are caried on the next generation, overpopulation nonewithstanding.
From an evolutionary point of view you would expect that we carried a strong innate propensity for heterosexuality, but the fact that homosexuality exists shows that this isn't the case. Calling it "non-innate" doesn't make it any easier to reconcile it with evolutionary theory because it just means that the "straight" gene is ineffective (as opposed to effective but not universally present) which is just about as much of a paradox.
So how to resolve it?
One possibility is that the gay gene didn't cause homosexuality in our evolutionary past so the selection pressure against it is a recent thing that hasn't had the time to weed out the gay gene yet. This could for example be the case if the social pressure against homosexuality used to be strong enough to overcome the gay gene's influence.
Another possibility is that it can under some circumstances be an advantage for a mother expecting her second son to imprint him against competing with his older brother but rather become a useful uncle. If this is the case we would expect homosexuality not to be genetic but to be determined by for example prenatal androgen exposure.

Thank you Helene_T for your calm, well-reasoned argument. I'd appreciate your comments on this new research.
https://www.telegrap...-homosexuality/

Sarah Napton, in today's Telegraph said:

Genes play just a small role in whether a person is gay, scientists have found, after discovering that environment has a far bigger impact on homosexuality.In the biggest ever study into the genetic basis of sexuality, researchers from more than 30 institutions including Cambridge University and Harvard, looked at the DNA of nearly 500,000 people in Britain and the US.They found that genes are responsible for between eight to 25 per cent of the probability of a person being gay, meaning at least three quarters is down to environment. Scientists said it worked in a similar way to height, in which genes are partly responsible, but other factors - such as nutrition - also play a major role, adding...

,

[kenberg]

The Telegraph wanted me to subscribe, but with Google help I found an article in the Harvard magazine

https://harvardmagazine.com/2019/08/there-s-still-no-gay-gene

I had seen something on this in the Washington Post as well.

The Harvard article includes some caveats, and as I recall the Post article did also. For example I would say that there is a big difference between "Once had a homosexual experience of some sort" and "Chose a life partner of the same sex". And then there is this issue of just what this 8 to 25 means. From the Harvard article: "In fact, the team estimated that the genetic variants they studied could predict, at best, somewhere between 8 percent and 25 percent of the reported variation in the entire cohort's sexual behavior." Meaning what, exactly?


But research quibbles aside, what we do with our lives presumably comes from some combination of genes, environment, luck and choice. I'm fine with trying to sort out the various cause and effects, but I would not expect definitive answers.


Well, I'm not Helene but I thought I would put in my two cents anyway.

[Winstonm]

An inability to locate a specific gene only tends to rule out single cause. Has there been a similar search for a specific sex drive gene? It would make more sense to me that both proclivities are housed within the human genome and normal variations within species emphasize one aspect more than another. This view would go a long way toward accepting and explaining that all types of sexual orientations are within the normal range of humanity.

The search for a specific gene seems naive to me as factors that affect gene expression are critical.

[barmar]

kenberg, on 2019-September-06, 12:17, said:

The Harvard article includes some caveats, and as I recall the Post article did also. For example I would say that there is a big difference between "Once had a homosexual experience of some sort" and "Chose a life partner of the same sex". And then there is this issue of just what this 8 to 25 means. From the Harvard article: "In fact, the team estimated that the genetic variants they studied could predict, at best, somewhere between 8 percent and 25 percent of the reported variation in the entire cohort's sexual behavior." Meaning what, exactly?
[size="3"]

This is normal statistics language. What it's describing is the degree of correlation between the genetic variation and the behavior variation.

For comparison, you've probably heard of BRCA, the so-called "breast cancer gene". There are actually two genes, called BRCA1 and BRCA2. The normal risk for a woman to get breast cancer is about 12%. But about 0.25% of the population have mutations in one of these genes (the normal genes actually protect against breast cancer -- genes are often named after the effects found in people with mutated variants), and in this case their chance of getting breast cancer is around 50%. I'm not sure exactly how this translates into the kind of percentage reported from the above study, but the point is that there's a relatively strong correlation between the genes and the disease (enough that some women who find out they have the gene get voluntary mastectomies, rather than wait to see if they get cancer -- actress Angelina Jolie did this).

I think that the 8-25% range cited above refers to the fact that there are a number of genes that are believed to be related to homosexuality, and they have different levels of correlation. Some are as low as 8%, while others are up to 25%. Similarly, my above BRCA description was simplified -- the estimated risk from the BRCA1 mutation is 55-65%, while BRCA2 is only 45%, and there's also a 3rd gene, PALB2, which has about 35% risk; so we might say that genetics predicts 23-53% of the risk (just being a woman predicts 12% of the risk).

[kenberg]

Barry, your post very well illustrates what I was getting at. You are not sure what the 8 % means exactly, neither am I. I can write down formulas, or look up formulas, for calculating correlations and I can understand them, so can you, but still I do not know, with any precision, what the 8% refers to.

Journalists often cite statistics. Often they do not understand just what these statistics mean, neither do the readers, but everyone thinks this is really conclusive of something because, well, after all, there was a definite number, 8 attached, so surely this must be conclusive of something.

I have told this story before but I was listening to a radio interview, the interviewer a serious guy usually, regarding capital punishment. A supporter was citing "45 % effect", an opponent was citing an almost negligible " 3 % effect", I kept waiting, in vain, for the interviewer to insist that each explain what their percentages referred to. Well, in this case the opponent start pushing on this, citing what his 3% referred to and how it was calculated, and then asked his opponent to do the same. She responded "I don't want to just throw numbers at you" and refused to discuss the numbers further. Often numbers just lie there, unexplained. Really conclusive but nobody know conclusive of what.

A journalist can just say the researchers view the evidence as strong without citing numbers, or s/he can also cite the numbers and then take the time to say just what it is that these numbers mean. I don't like it when they put numbers out with no explanation at all as to what they actually mean. Statistics can be useful, but it is best if their meaning is explained.

[helene_t]

I agree that it is a bit cryptic what those 25% mean. When the outcome is quantitative, say IQ or height, it is maybe easier to explain.

Maybe it is helpful to think of it this way. Sexual orientation could be accurately predicted by four different factors, uncorrelated with each other, and each on its own correlating equally strongly with sexual orientation.

One of those four factors summarises a subjects genotype with respect to the five genes identified in the study.

The other three are "environmental", which are at present not identified but could be anything from uterus chemistry to video games exposure during early adulthood and availability of suitable same-sex partners at the local dating scene.

Whether measurement errors (for example respondents being embarrassed to tell the truth) contributes to the 75% is not entirely clear, and one may also wonder if part of the "genetic" effects could be due to confounding between ethnicity and relevant environmental factors. So there could be so dispute about the exact number.

And maybe genetic effects to subtle to uncover by the models used by the researchers could also play a role.

Anyway, 25% doesn't sound hugely surprising. My gut feelings would have been a somewhat lower number although 0% would have surprised me a bit.

Since this thread is about unpopular opinions more widely I would like to mention that I actually like pie charts and I don't care that it marks me as a non-serious statistician.

[barmar]

helene_t, on 2019-September-08, 01:57, said:

Anyway, 25% doesn't sound hugely surprising. My gut feelings would have been a somewhat lower number although 0% would have surprised me a bit.

It's probably surprising to all the people who feel they were "born this way".

However, these findings should not be considered a vindication of the people who say that it's a choice, either. There are many other factors.

In fact, you can be born this way even if it doesn't show up in the genes -- the environment in the womb has strong effects, so the mother's genes and/or diet could be part of the story.

This is such a complex mixture of behaviors that it's foolish to think that it can be pinned down to any narrow set of identifiable causes.