[nige1]

barmar, on 2015-June-09, 09:29, said:

This is why it's so hard to use rational arguments to convince people to give up ingrained beliefs like religion, sexism, and racism.

IMO, it's OK

• To believe in concepts that we can't prove (or disprove) by science or logic. Many of us are motivated by money, power, rights, or religion, without really knowing why.
• To recognize sexual differences, both physical and mental. For example, historically, most geniuses appeared to be men. Psychologists used to explain that the spread of intelligence was greater in men (there were more geniuses -- but there were also more idiots and morons). Nowadays, in the UK, women achieve better examination results than men, at all levels, and in all subjects (including traditional male enclaves, like Mathematics and Engineering). Presumably, in the past, all they lacked were opportunity and recognition. Are there other factors?
• To accept that there are ethnic differences: mental differences as well as obvious physical differences. Thus, I think Eysenck was right about the IQ of oriental people (e.g. they're innately better at Mathematics). Personality differences are also worth investigation.
• (For completeness, although I'm not a homophobe) In an over-populated world, homosexulaity has obvious merits. Nevertheless, I confess I can't believe that homosexuality is innate.

IMO all such subjects should be open to discussion and research should be encouraged, in as unbiased a way as we can achieve. Separating genetic from cultural and environmental influences might be hard but burying our heads in the sand doesn't really help us to fight prejudice.

[Winstonm]

nige1, on 2015-June-09, 10:30, said:

IMO, it's OK

• To believe in concepts that we can't prove (or disprove) by science or logic. Many of us are motivated by money, power, rights, or religion, without really knowing why.
• To recognize sexual differences, both physical and mental. For example, historically, most geniuses appeared to be men. Psychologists used to explain that the spread of intelligence was greater in men (there were more geniuses -- but there were also more idiots and morons). Nowadays, in the UK, women achieve better examination results than men, at all levels, and in all subjects (including traditional male enclaves, like Mathematics and Engineering). Presumably, in the past, all they lacked were opportunity and recognition. Are there other factors?
• To accept that there are ethnic differences: mental differences as well as obvious physical differences. Thus, I think Eysenck was right about the IQ of oriental people (e.g. they're innately better at Mathematics). Personality differences are also worth investigation.
• (For completeness, although I'm not a homophobe) In an over-populated world, homosexulaity has obvious merits. Nevertheless, I confess I can't believe that homosexuality is innate.

IMO all such subjects should be open to discussion and research should be encouraged, in as unbiased a way as we can achieve. Separating genetic from cultural and environmental influences might be hard but burying our heads in the sand doesn't really help us to fight prejudice.

What I get from your description is that point A) "that it is OK to believe in concepts that we can't prove" is used as justification for points B, C, and D.

Personally, I don't grasp point A. What is the point in "belief"? The best we as humans can do is to surmise the unknown based on available data and current knowledge - use of our inductive reasoning processes. Looking for magical answers to me is simply childish.

[billw55]

nige1, on 2015-June-09, 10:30, said:

• To accept that there are ethnic differences: mental differences as well as obvious physical differences. Thus, I think Eysenck was right about the IQ of oriental people (e.g. they're innately better at Mathematics). Personality differences are also worth investigation.
• (For completeness, although I'm not a homophobe) In an over-populated world, homosexulaity has obvious merits. Nevertheless, I confess I can't believe that homosexuality is innate.

I suspect that mathematics is not an innate human ability at all, i.e. that it is 100% learned.

And on not accepting that homosexuality is innate: can you say why you consider that impossible?

[mikeh]

nige1, on 2015-June-09, 10:30, said:

IMO, it's OK

• To believe in concepts that we can't prove (or disprove) by science or logic. Many of us are motivated by money, power, rights, or religion, without really knowing why.
• To recognize sexual differences, both physical and mental. For example, historically, most geniuses appeared to be men. Psychologists used to explain that the spread of intelligence was greater in men (there were more geniuses -- but there were also more idiots and morons). Nowadays, in the UK, women achieve better examination results than men, at all levels, and in all subjects (including traditional male enclaves, like Mathematics and Engineering). Presumably, in the past, all they lacked were opportunity and recognition. Are there other factors?
• To accept that there are ethnic differences: mental differences as well as obvious physical differences. Thus, I think Eysenck was right about the IQ of oriental people (e.g. they're innately better at Mathematics). Personality differences are also worth investigation.
• (For completeness, although I'm not a homophobe) In an over-populated world, homosexulaity has obvious merits. Nevertheless, I confess I can't believe that homosexuality is innate.

IMO all such subjects should be open to discussion and research should be encouraged, in as unbiased a way as we can achieve. Separating genetic from cultural and environmental influences might be hard but burying our heads in the sand doesn't really help us to fight prejudice.

I love this post and the sentiments expressed therein [/sarcasm]

Let's look at this: we start with the proposition that it is 'OK' to hold beliefs unsupported by rational evidence, such as beliefs in religion or that homosexuality is a learned behaviour/choice.

We end with the proposition that 'discussion and research' should be encouraged in order to fight prejudice!

Guess what?

There has been a great deal of careful, scientifically tested research into, amongst other topics you mention, the origins of homosexuality, including studies of non-human species, and the overwhelming preponderance of the evidence appears to be that homosexuality is merely part of the spectrum of human sexuality, and is present to varying degrees in a number of other species as well.

Anyone with any tiny amount of curiosity on this issue can find examples of this literally within seconds.

However, you specifically advance your bigoted (because it is a belief to which you hold with no rational basis) opinion and claim that it is OK for you and others of like bigoted thinking to do so.

Guess what?

I agree with you. It is perfectly OK, as far as I am concerned, for you to live your life believing that homosexuality is not innate.

But, and this is a big but, as soon as you or any other such bigot advocates that gays should be discriminated against in any fashion, for being gay, then it is NOT OK.

In a similar vein, if you want to see an oriental (whatever that means) as mathematically smarter than you by virtue of that person's genetic makeup, feel free to do so. I suspect, and hope I am wrong, that this was put forward by you as a dogwhistle.....by saying that orientals are in some way smarter than whites, you pander to or maybe even believe that other ethnicities are inherently inferior to whites.

Take a look at the research into how expectations influence test performance amongst black US students, or female students and you may come to learn, rather than to 'believe', that crude measurements of relative performance between ethnicities isn't necessarily reflective of genetic makeup, but is, rather, very heavily influenced by cultural factors.

I could go on at length, but the short answer is that I am happy to defend your right, and the right of anyone, to hold to beliefs that lack any rational basis, so long as you don't allow those beliefs to cause harm to those who don't share them. Be a bigot in your own mind as much as you want. It is your loss when you live inside the walls of your beliefs, even tho, ironically, those beliefs no doubt make you feel smug and superior. But it is a loss to society as a whole when you and others of like mind allow those beliefs to influence how you interact with the rest of us.

Go ahead and worship a god of your choosing, but don't make non-believers pay taxes to support your religion. Go ahead and pray to your god as often as you like, but don't punish or discriminate against atheists or believers in other religions merely because they don't share your 'faith'. And so on.

EDIT:

I want to stress that I have no reason to believe that you in any way discriminate against anyone by virtue of your beliefs. When I describe those beliefs as bigoted, I do not mean to suggest that you act as a bigot in any fashion: to the contrary, based on your posts here, which is all I have to go on, my assumption is that you treat people fairly even while believing some irrational things about them. If so, then I would gladly defend your right to hold such beliefs, while hoping that at some point you'd examine them more closely, and in the light of available evidence.

[MrAce]

Mike for president!

[kenberg]

Homosexuality. I don't want to discuss another person's sexuality but suffice it to say that when I look at close friends and family this discussion is not totally abstract. I see it this way: I don't need to know if it is or is not totally a matter of genetic destiny. It seems extremely unlikely to me that a heterosexual wakes up one morning and, with nothing else to do, decides to become gay. But surely it is not this simple. My general view of life is that we are all a combination of genes, environment and personal choice. I see no reason at all to judge another person on the basis of their sexual choices, regardless of whether it is a choice or not, so outside of scientific interest, who cares?

Bill mentioned mathematics, that it is not innate at all. I think I disagree. Again, there is a combination of factors. But I just took to math at a fairly early age. It certainly did not come from parental encouragement. I always thought that if I someday told my father I was quitting college and taking up carpentry he would have breathed a sigh of relief. Somehow, I just took to it. As with sexuality, I feel no need to explain.

Race is tough. Let me come at it from a different way. largely I don't know who is Jewish and who is not, but I am pretty sure that Jews are represented in the upper level of mathematics in far greater numbers than you would expect from their numbers in the world population or the US population. I am not Jewish. Again so what So So So What What What! I do ot know if there is something in Jewish genes that relates to this, nor do I care. I know Protests, Jews and Catholics who are better at mathematics than I am, I I also know some of each who are not as good as I am.
Getting to black/white, we most unfortuantely have to keep data. I had a graduate assistant who was extremely talented and he had features that might have indicated African ancestry. I was asked by someone who had to count such things what his race was. I said I did not know and I had no intention of asking him.

It is natural for me, or so I like to think, to treat individuals as individuals. It is not something I do after moral reflection, I just do it. I think that we have gone totally off the deep end in slicing, dicing and cataloging.

[hrothgar]

mikeh, on 2015-June-09, 12:16, said:

Take a look at the research into how expectations influence test performance amongst black US students, or female students and you may come to learn, rather than to 'believe', that crude measurements of relative performance between ethnicities isn't necessarily reflective of genetic makeup, but is, rather, very heavily influenced by cultural factors.

I think that this topic deserves a bit longer treatment.

I have done some reading on whether there is any kind of statistically significant relationship between race and performance on standardized tests.
As I recall, virtually all reputable studies assert that demographic influences swamps any possible genetic relationships.

By which I mean that issues such as

• Parental income
  
• Quality of the school system
  
• Parent's education achievement
  
• Two parent households

are so much more important that the question of ethnicity isn't of any real interest

[mikeh]

Incidentally, even if, and this is a huge 'if', there were any validity to the notion that one 'race' (whatever that term means) has greater or lesser abilities in any given realm of human activity than another, it seems almost surely to be 'on average'.

The notion that a Chinese or Japanese or other 'oriental' is going to be better at math than a white or black or brown person (assuming that we define oriental to exclude these 'categories') is nonsensical.

I recently read of an explanation for why Africans or those of fairly recent African extraction (read: descendants of slaves) tend to be disproportionally represented in the higher ranks of athletes.

That notion is that it has nothing to do with any inherent 'racial' characteristic, but is rather reflective of the basic fact that those 'races' based in Africa exhibit a greater variety of DNA/genetic makeup than do populations based in other parts of the world.

This makes sense to me, if we assume, as appears to be likely, that homo sapiens sapiens originated in Africa, spread widely throughout the continent, and then saw small populations emigrate out of the continent.

Those small populations would be closely linked genetically and would represent a narrow range of genetic diversity, being a subset of the genetic diversity that remained in Africa and continued to diversify.

Hence in Africa we find peoples who, on average, are taller than peoples elsewhere, and we also find peoples who are smaller than elsewhere....the range of human expression is greater in Africa than elsewhere.

Thus those at one end of the bell curve, the 'normal' distribution of human abilities, are likely to be further 'out', to either end of the curve, in African based populations than those whose genome went through the bottleneck of a small population leaving Africa.

For every Kenyan marathon runner, there will be someone else from an African background who is even more inept at distance running than I am! Because the base of their bell curve is simply wider than the base of the bell curve of those of my ancestors who left Africa for Europe all those years ago.


As for cognitive issues, there I am not so sure, but I do think that culture, opportunity (read: wealth, education) and expectations play a huge role, and my uninformed lay speculation is that culture effects swamp genetic effects in cognitive matters.

For example, having reference to the presence of Jews in many aspects of western culture involving use of intellectual skills, consider the cultural history of the West over the past 1000+ years.

It is only recently (in historical terms) that Jews have been allowed to be politicians, or to join the 'right' business clubs. It is only recently, again in historical terms, that gentiles were allowed to charge interest!

So Jews traditionally tended to be present in disproportionate numbers in banking, and the professions associated with banking, including law and accounting. They couldn't be 'gentlemen'. They had to earn their money, and for many of them that required getting a good education in arithmetic and accounting at a time when upper class gentiles scorned those who earned a living, and thought that studying ancient greek and memorizing the roman poets was the highest form of education.

Not surprisingly, children tend to some degree to follow in the footsteps of their father (bear in mind we are speaking of a time when women were chattels or ornaments or baby factories), and so cultural expectations would grow.

Is this valid or mere armchair speculation? I don't claim to know, but I do offer these thoughts in support of my view that it is wrong to posit or infer that any group of humans, identified by the frankly bizarre term 'race', have any innate advantage or disadvantage over others, as opposed to the material advantages that arose from the sort of factors described by Diamond in his wonderful book Guns, Germs and Steel.

Edit: Richard, characteristically, summarized what I was trying to say in a post that he put up while I was meandering though mine

[kenberg]

hrothgar, on 2015-June-09, 16:43, said:

I think that this topic deserves a bit longer treatment.

I have done some reading on whether there is any kind of statistically significant relationship between race and performance on standardized tests.
As I recall, virtually all reputable studies assert that demographic influences swamps any possible genetic relationships.

By which I mean that issues such as

• Parental income
• Quality of the school system
• Parent's education achievement
• Two parent households

are so much more important that the question of ethnicity isn't of any real interest

Agreed, as far as it goes. But for me, the starting point is to treat individuals as individuals. If we go to the items you mentions:

My father had an eigth grade educaion, my mother a little high school. These are my adoptive parents. My genetic parents both finishe eigth grade (or so I understand). I had a two parent upbringing but my father had a stroke and my mother drank too much. So effing what. I'm me.

If we are to make a rule that African Americans are 12% (or whatever the number is) of the population so of course 12% of the mathematics faculty at Princeton should be African American then we have to deal with all sorts of things. If we instead take the view that everyone benefits when individuals find a path to fulfillment, basketball, mathematics or corporate jungle, (ok, preferably not stripper or con man) then we can back off of the racial, gender and other classifications.

Providing opportunity is a tough job, and there are times that I think we have not progressed much. In some cases yes, but some of the schools today are atrocious. Which, of course, is your second item and critical. We have kids in awful circumstances going to awful schools and the only thing we think of is gettnig them ready for college. This is, I think, a serious error. Idealists should start the day by reciting three times "It is possible that not everyone wishes to be just like me".

Anyway, I have always strongly resisted being tied in a box and labeled, and I apply the same attitude toward others.

[nige1]

Winstonm, on 2015-June-09, 12:02, said:

What I get from your description is that point A) "that it is OK to believe in concepts that we can't prove" is used as justification for points B, C, and D. Personally, I don't grasp point A. What is the point in "belief"? The best we as humans can do is to surmise the unknown based on available data and current knowledge - use of our inductive reasoning processes. Looking for magical answers to me is simply childish.

I think it's OK to believe ideas that we can't prove or disprove, by science or logic. For example human rights.
We can find out more about differences in ability and personality between sexes and among ethnic groups. I think we should do so but that is the question posed in this topic.

billw55, on 2015-June-09, 12:05, said:

I suspect that mathematics is not an innate human ability at all, i.e. that it is 100% learned.And on not accepting that homosexuality is innate: can you say why you consider that impossible?

On the evidence of which I'm aware, I can't believe homosexuality is innate More evidence might convince me, either way.
Similarly, the evidence, of which I'm aware, shows that mathematical ability is partly inherited. Again, I'm open to evidence and argument.

mikeh, on 2015-June-09, 12:16, said:

However, you specifically advance your bigoted (because it is a belief to which you hold with no rational basis) opinion and claim that it is OK for you and others of like bigoted thinking to do so.

It's hard to argue with Mikeh because he misrepresents my views, attacking me personally, impugning my knowledge, character, and motives. As many threads in BBF will testify: I don't claim specialist knowledge: I'm delighted to learn. A bigot is a person intolerant of other opinions: I change my views in the light of evidence and argument. Mike's arguments haven't convinced me yet

[helene_t]

nige1, on 2015-June-09, 10:30, said:

In an over-populated world, homosexulaity has obvious merits. Nevertheless, I confess I can't believe that homosexuality is innate.

Why don't you think it is inate?

It probably isn't 100% inate 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 presure 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 inate conditions have a substantial influence.

Your remark about overpopulation suggests that one reason why you don't believe it to be inate 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 inate propensity for heterosexuality, but the fact that homosexuality exists shows that this isn't the case. Calling it "non-inate" 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 ge genetic but to be determined by for example prenatal androgen exposure.

[kenberg]

I never would have expected homosexuality and mathematics to appear together in a discussion of genetic per-disposition but actually it makes some sense to compare them. At any rate, I watched the following yesterday.

I was in Starbucks and there was a mother and her young son nearby. The floor was tiled with squares, except for the area just inside the entrance which was a rectangle of other material. The boy got up, as kids will do, and paced around a bit. Walking along the edge of the rectangle he announced that it was six squares long. How much in the other direction, asked his mother. Four, after counting. How many tiles would be needed to fill that area with tiles? Hesitancy. What's 6 times 4? Hesitancy. Some guidance occurs. Suppose you have 2 rows of 6 tiles, how many? 12. And with another row? After a pause, 18. And the next? 24. Yes 4 times 6 is 24.

A lot was being learned in this casual occurrence. 4 times 6 is 24 not just because the teacher says so by because if you add 4 sixes you get 24.
The fact that 4 times 6 is 24 can be used to quckly count the number of tiles in a rectangle.
Very important: We can count the number of tiles in an imagined rectangle.

I considered going over and expressing my pleasure to mother and child but rightly or wrongly chose to mind my own business.

Some thoughts:
The kid was interested in this. I never got the impression that the mother was at all insisting that her son work this through. She was there to help if he wanted the help.
It would never occur to some mothers (or fathers or older siblings) to help/
Some kids would absolutely have no interest in the posed problem.

How much of this was genes, how much environment? Beats me, but i sure enjoyed watching it.


Going back, if we must, to homosexuality. I imagine that it is very much ingrained, which is not quite the same as saying that it is genetic. Sex is a complicated business and we all are guided by civilization to deal with this in ways that may not be entirely in line with our genetically induced inclinations. So there is some sexual learning that takes place in all of us. If a person, as s/he matures, finds himself or herself naturally drawn sexually to someone of the same sex, why must I have a defendable opinion as to whether this comes from a gay gene or from the totality of his/her genetics and experience? Why is it even my business? Under suitable circumstances I may well value a discussion with someone about various choices that I may make in life, but I get to choose whether and with whom.

[mikeh]

nige1, on 2015-June-09, 20:54, said:

I think it's OK to believe ideas that we can't prove or disprove, by science or logic.[size="2"]
Similarly, the evidence, of which I'm aware, shows that mathematical ability is partly inherited. Again, I'm open to evidence and argument. It's hard to argue with Mikeh because he misrepresents my views, attacking me personally, impugning my knowledge, character, and motives. As many threads in BBF will testify: I don't claim specialist knowledge: I'm delighted to learn. A bigot is a person intolerant of other opinions: I change my views in the light of evidence and argument. Mike's arguments haven't convinced me yet

Strange. I think I captured your views perfectly. You expressly claim that it is 'OK' to hold beliefs that are unsupported by evidence. You state that you 'can't believe that homosexuality is innate'.

A moment's research,using google, would lead you to learn that the majority of non-religious experts on the subject see compelling evidence that homosexuality has a significant innate component. The only experts who seem to disagree are those with a clear religious bias. As is so often the case, religion obstructs rational thinking.

You are either happy to cling to an unsupported belief without looking into the evidence that would show you your error, or you are allowing your desire that your religious beliefs be correct to cause you to find objective evidence to be unacceptable. In either case, you are exhibiting a way of thinking that is prototypically that of a bigot. I assume that in social interaction you suppress the expression of these beliefs out of some sense of decency.

As for impugning your knowledge.....you do that yourself by your own words. It is ridiculous for you to announce that you 'cannot believe' something for which there is readily available and compelling evidence and then claim that your knowledge or motives are being unfairly described. You want people to applaud your wilful ignorance? Go to a website for people who reject evidence that contradicts their prejudices. That is who you are, by your own admission.

Ask yourself this: why is it that you feel that you 'cannot' believe that homosexuality is innate? You were already challenged to answer that question, and it is telling that you have ducked the question, while whining that you have been unfairly called out for thinking, not acting, like a bigot. Sorry, but the way to avoid being called a bigot is to stop exhibiting bigoted thinking.

Btw, you reveal more of your ignorance when you suggest that we can't prove that ideas such as human rights can be shown logically to be a good thing (I am paraphrasing). This sort of statement is often made by the religious who claim that morality is something that is to be imposed or learned from religion. In fact, a moment's research would lead you to a number of explanations for the existence of morality, including by extension, the notion that humans owe each other ethical obligations known as human rights. The fact that you appear to be unaware of these arguments reflects not on the lack of such arguments but on your knowledge. When someone makes statements of belief without appearing to have any interest in whether his statements are valid, then that person should expect to be called out for his ignorance. You don't like it? Then open your mind to the notion that your beliefs may be invalid.

Keeping your mind firmly closed by rejecting evidence that conflicts with your belief structure or refraining from searching it out when challenged merely reinforces the validity of my description of you. I do find it ironic that someone can make the claim that he rejects a concept because he 'cannot believe' it and simultaneously proclaim that his views are based on evidence

[Cyberyeti]

On the homosexuality front, I can only present my own observation of friends without comment.

Second time round I went to a university that was at the time very left wing and gay friendly (UEA). I witnessed a number of friends arrive either uncertain of their sexuality or straight. Within a year or so they'd come out as gay. After leaving the environment, most of them decided they were in fact straight within a year or two.

I have no problem with people who believe in any religion, so long as they don't try to force their religion on me by for example trying to enshrine in law stuff that I don't believe to make abortion illegal. Also things like believing that the earth is only 6000 years old that are easily disproved by simple science and asking for it to be taught in schools deserve no respect.

[billw55]

Cyberyeti, on 2015-June-10, 08:24, said:

Second time round I went to a university that was at the time very left wing and gay friendly (UEA). I witnessed a number of friends arrive either uncertain of their sexuality or straight. Within a year or so they'd come out as gay. After leaving the environment, most of them decided they were in fact straight within a year or two.

It sounds like they were unsure, experimented, and reached a conclusion. A reasonable process. I am glad they were able to find a welcoming environment for it.

[barmar]

Intuitively, it might seem like homosexuality can't be genetic -- homosexuals don't generally have children, so they can't pass on the "gay genes". But genetics is much more complicated than that. There are many genes that are present throughout the population, but they aren't expressed by everyone who holds them. Think of them like the airbag in a car: every modern car has it, but it only gets used when the car gets into a crash. Similarly, there are genes that only result in the corresponding trait a certain percentage of the time -- when they exist in combination with other genes, or in response to environmental stimulus, or some combination of both. If a number of gays is beneficial to the human species as a whole, the genes will persist, because people who hold the gene but don't actually become gay will pass it on.

As another example, scientists know the precise genetic cause of sickle cell anemia. You'd assume that a gene that almost invariably kills its holder (before modern medicine) could not take hold in a population. But it's a recessive gene -- you have to have a copy from both parents to get the disease. But if you just have one copy, it turns out that protects you from malaria. The result is that the gene finds a balance in the population: enough people have it that the protection from malaria cancels out the propensity towards sickle cell.

[billw55]

barmar, on 2015-June-10, 09:15, said:

... homosexuals don't generally have children, ...

Much of your argument is good. But I would also point out that this bit is not really true. In the past, it was fairly common, due to social pressures, for gays and lesbians to marry against their preference, and to have children. That might decline in a more accepting society; I wonder if it has been studied.

[barmar]

billw55, on 2015-June-10, 09:37, said:

Much of your argument is good. But I would also point out that this bit is not really true. In the past, it was fairly common, due to social pressures, for gays and lesbians to marry against their preference, and to have children. That might decline in a more accepting society; I wonder if it has been studied.

Hence my qualifier "generally". They almost certainly didn't procreate at the same rate as heterosexuals.

[mikeh]

barmar, on 2015-June-10, 09:15, said:

Intuitively, it might seem like homosexuality can't be genetic -- homosexuals don't generally have children, so they can't pass on the "gay genes". But genetics is much more complicated than that. There are many genes that are present throughout the population, but they aren't expressed by everyone who holds them. Think of them like the airbag in a car: every modern car has it, but it only gets used when the car gets into a crash. Similarly, there are genes that only result in the corresponding trait a certain percentage of the time -- when they exist in combination with other genes, or in response to environmental stimulus, or some combination of both. If a number of gays is beneficial to the human species as a whole, the genes will persist, because people who hold the gene but don't actually become gay will pass it on.

As another example, scientists know the precise genetic cause of sickle cell anemia. You'd assume that a gene that almost invariably kills its holder (before modern medicine) could not take hold in a population. But it's a recessive gene -- you have to have a copy from both parents to get the disease. But if you just have one copy, it turns out that protects you from malaria. The result is that the gene finds a balance in the population: enough people have it that the protection from malaria cancels out the propensity towards sickle cell.

My understanding is the concept of epigenetics has caused a significant rethinking of the nature of the relationship between DNA and the characteristics of the organism in which the DNA is found. I have read a lot of 'books for the layperson' about evolution (almost all of Dawkins, almost all of Gould, and a number of other books as well) but not much at all about epigenetics, beyond a few articles here and there. It does seem to suggest that what counts most, in terms of relating genes to organisms is how and if any particular gene or combination of genes is 'expressed' or turned on, and that the factors that govern that are extremely complex, which makes nothing but sense to me.

I gather that whether and how genes are expressed can depend on the external environment (external to the DNA molecule) such as the presence of various chemicals in the cells, which in turn presumably can arise from the biochemistry of the mother (as one source) or the presence or absence of chemicals in her environment.

I also understand that many variations in humans, caused by genetic differences, are associated with a number of genes, rather than any single 'gene for baldness' or 'gene for obesity'. I express no opinion on whether this is true for that aspect of sexuality that is genetically influenced, since I lack any knowledge of the state of research in that area. I do gather that there is some basis for thinking that biochemistry of the mother during pregnancy can influence outcomes, and that accords with my sketchy understanding of epigenetics (tho I may be woefully inaccurate).

I find it fascinating to be alive during this phase of the struggle for understanding of our universe....pushing back the areas in which superstition and belief shutter the human spirit and opening up the grandeur of how the universe is for us to at least glimpse. I find it even more fascinating that many of those with true expertise have a passion for sharing this with those of us who are merely spectators.

[billw55]

barmar, on 2015-June-10, 09:41, said:

Hence my qualifier "generally". They almost certainly didn't procreate at the same rate as heterosexuals.

I suppose that is true, except perhaps in cases where procreation was not voluntary. This is still heard of now, and was probably more common in the past.