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From The Huffington Post:

For even without a causal link established between homosexuality and population management, the obvious reduction in population growth attributable to homosexuality by itself indubitably works to preserve the species. (Emphasis mine)

So "homosexuality by itself indubitably works to preserve the species", really?

Thus, my question is: Does homosexuality work to preserve the species?

Carlo Alterego
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    I would argue that this question has an invalid premise. Natural selection operates at the level of genes, and is not "concerned" with preserving a species. http://en.wikipedia.org/wiki/Gene-centered_view_of_evolution#Overview Recent evidence is that homosexuality is not genetically determined but epegentic. http://www.genengnews.com/gen-news-highlights/epigenetics-underpins-homosexuality/81247763/ This would make any sort of idea that there is a selective pressure FOR homosexuality false. – Robert Kaucher Jan 02 '13 at 21:49
  • No Robert, the "question" does not have premise, so no "invalid premise" can exist. – Carlo Alterego Jan 03 '13 at 10:05
  • The idea that evolution works to preserve the species at the cost of preserving the gene is a premise implied by the question and contradicted by the comment by @Robert. – Oddthinking Jan 03 '13 at 11:26
  • Hello @Odd, I'm not aware of having premise a so complicated argument ("evolution works to preserve the species at the cost of preserving the gene")! – Carlo Alterego Jan 03 '13 at 13:03
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    I agree with Carlo here. The claim could be "rainfall works to preserve the species" and it would still be valid. There is no need to even accept evolution at all to make this a valid claim (remember: valid, does not mean necessarily correct!) – Sklivvz Jan 03 '13 at 13:09
  • Hello @Sklivvz, yes, I'm astonished at how little the ratio [votes]/[viewed] (0,028 just now) is, nevertheless I'm sure the question is one of the better I have seen here. – Carlo Alterego Jan 03 '13 at 13:19
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    @Sklivvz: I see your point, just. The Huffington Post article explicitly introduces the concept of homosexuality being an evolutionary adaptation to overpopulation. Where the quote starts with "For even without a causal link", Robert effectively argues "There can be no causal link. That whole half of the article is a furphy based on a misunderstanding of evolution." – Oddthinking Jan 03 '13 at 13:43
  • Once we remove that concept, the question breaks into two parts: (a) Does homosexuality reduce population growth? (b) Does reduced population growth "preserve the species"? – Oddthinking Jan 03 '13 at 13:45
  • I will remove the additional two cites. One argues that homsexuality in penguins may be adaptive; in Macaque Monkeys maybe not. Neither is about preservation of species. The second doesn't seem to talk about preservation of species at all. – Oddthinking Jan 03 '13 at 13:52
  • Yes @Odd, but, presumably, you are forgetting that in ancient Greece "[t]he formal practice, an erotic yet often restrained relationship between a free adult male and a free adolescent, was valued for its pedagogic benefits **and as a means of population control**," Wikipedia says. Yet, yes, Mr. Bailey said: "[H]uman homosexuality? **To be sure** "there can be crosstalk" between the disciplines of human and animal study." – Carlo Alterego Jan 03 '13 at 13:53
  • re: Your first quote - wasn't mentioned in the article. re: your second - yes, but the 'crosstalk' is about whether homosexuality is an adaptation, rather than preserving species. We may have a misunderstanding about what that term means. – Oddthinking Jan 03 '13 at 13:56
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    The population issue is a distraction. It is possible that homosexuality-genes (if they exist) *enhance* the number of surviving children in a population, so they may have arisen and survived because they *increase* population not because they control it. – matt_black Jan 03 '13 at 16:23
  • @matt_black - But that is not what the article asserts nor what the resulting question asks. While certainly an interesting question, it is (IMO) off topic here. – Robert Kaucher Jan 03 '13 at 20:00
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    Noting the new bounty, I maintain "preserving the species" has no clear meaning, so you won't get any high-quality, definitive answers. Which of the following counts as "preserving a species"? 1) Increasing the population? 2) Decreasing the population? 3) Preserving the current distribution of genes? 4) Changing the relative distribution of genes (as homosexuality is alleged to do, and thus changing (not preserving) the species)? Does the homosexual behaviour of chimps preserve the species? If so, why aren't we all still preserved at the same common ancestor? – Oddthinking Jan 07 '13 at 11:54
  • I guess you could (try to) make the same case for sterility? – Benjol Jan 07 '13 at 12:36
  • @Benjol, no, I cannot because there are no evidences revealing genetic causes of sterility. Questions here have to have some basis, as well. – Carlo Alterego Jan 07 '13 at 13:58
  • I've been saying this since I learned what homosexuality was at age 9; it's common sense. – Sandwich Jan 07 '13 at 16:21
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    @DSKVR: You've been saying since 9 years old that homosexuality preserves the species? That's pretty impressive thinking for a 9 year old. Still wrong, but impressive :-) – Oddthinking May 20 '13 at 17:10
  • @Carlo: You seem to be bumping and throwing bounty at this question, and but remain unhappy with the result. Why are you unhappy with the existing answers? Are they understandable to you? Would you consider clarifying the question given it is ambiguous? – Oddthinking May 20 '13 at 17:18
  • Odd, I'm under the impression that the answers do not contain enough detail, and perhaps they can be improved. But to my mind, the mind of a standard person, the question is pretty clear :) – Carlo Alterego May 20 '13 at 17:23
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    @Carlo_R. The problem with the question is that there is no evidence to support the claim and therefore there is no satisfactory "yes" answer. We know some homosexuals still reproduce, we know that the human population is still growing exponentially, and we know that in historical examples of out of control populations in other mammals their numbers are regulated by things like famine, disease, and/or increased predation NOT by increased instances of homosexuality. We cannot prove a negative. There is no evidence to support the `indubitable` claim in the question. – Robert Kaucher May 20 '13 at 19:00
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    Maybe I'm missing something, but how the "gene" would be selected if it existed to limit the expansion of population? Either it works then it is not selected (limited reproduction) or it doesn't work and it is selected (normal reproduction)... quite a paradox. – Zonata May 20 '13 at 19:30
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    @RobertKaucher We don't close questions just because a negative answer to them can't be proven. –  May 21 '13 at 05:09
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    @Sancho - Where did you derive the view that I am suggesting the question be closed? I am suggesting the questioner is dissatisfied with the answers in the negative because the question starts with a premise, expressed in the quotation from the article, and all that those who answer can do is to attack the premise as unfounded. We cannot increase the detail as the OP suggests in the bounty because none exists. I have expressed this repeatedly. I have never stated the question should be closed. – Robert Kaucher May 21 '13 at 13:24
  • @Oddthinking If you can you prove that it is not possible, I will reconsider my deductions. – Sandwich Jun 24 '13 at 23:05
  • The quoted claim doesn't claim that "homosexuality preserves the species". It claims three separate things 1: "there is an obvious reduction in population growth", 2: "the obvious reduction in population growth can be attributed to homosexuality", and 3: "the obvious reduction in population growth indubitably works to preserve the species". All three of those need to be true for the claim to be true. Show that any of them is false, and the claim falls. –  Nov 01 '13 at 17:22

4 Answers4

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Two things that are often overlooked in discussions of evolution, particularly when it comes to sexual behaviour, are sexually antagonistic traits and epigenetics. Recent studies indicate that homosexuality may be due to a normally beneficial epigenetic mechanism that occasionally malfunctions. If this is the case, then homosexuality is an abnormal consequence of a beneficial trait, and so there is no reason it should have been selected out of the gene pool.

W. R. Rice et al., “Homosexuality as a consequence of epigenetically canalized sexual development,” The Quarterly Review of Biology, 87:343-368, 2012

Isaac
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  • What's the format for citation? There is a paper cited at the bottom of my second link. – Isaac Jan 03 '13 at 22:39
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    Hello, Isaac and welcome to Skeptics! Great first answer. – Sam I Am Jan 04 '13 at 05:45
  • I’m averse to words such as “abnormal” and “beneficial” which clearly carry judgement and normally have no meaning in biology – of course we speak of “averse” conditions in the case of an illness but redefining homosexuality as an illness is something we’ve transcended. – Konrad Rudolph May 20 '13 at 18:40
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    @KonradRudolph According to Merian-Webster abnormal signify: deviating from the normal or average. However, I agree that to most of us, it carries a pejorative meaning. – Zonata May 20 '13 at 22:03
  • @Zonata What’s the norm? In the context of biology, talking about a “norm” is almost always a fallacy (in fact, according to some, such as Daniel Dennett, it’s the reason why the theory of evolution was discovered so late, because scientists clung to an Platonic ideal of form). – Konrad Rudolph May 20 '13 at 22:56
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    @KonradRudolph It is the average, thus the majority. In the case of sexual orientation, a very strong majority of persons are heterosexual. To me it does not carry any other meaning than that. But again, I agree with you that to most being abnormal is pejorative thus it is a word I use carefully in daily life. – Zonata May 21 '13 at 00:45
  • Reading the paper's conclusions, it seems that they are saying that the phenotype is strongly influenced by fetal androgen signalling, and that there is a wide variation in response. And so homosexuality is little different from other apparently unusual phenotypes with reduced Darwinian fitness such as hypospadias, Cryptorchidism and female idiopathic hirsutism. It is thus not a malfunction but a normal distribution of response which one expects in biological systems. – HappySpoon Jun 30 '14 at 20:55
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Due to some very apt criticism regarding my comment on the question I am going to rephrase it as an answer. It is not so much that the question has an invalid premise, but that the cited article that generated the question is based on an invalid premise.

We know as a fact that homosexuals do conceive children.1 The idea that they do not is false and the idea that they did so less than heterosexuals in the Environment of Evolutionary Adaptedness is likely completely untestable. We would really need research to test this claim and none exists. The notion that this idea is in any way indubitable is just foolish. And consider this: if that is what homosexuality is supposed to be "for", then it is doing a very, very poor job considering the continued exponential growth of the human population2. Also, recent evidence is that homosexuality is not genetically determined but epigentic. This would make any sort of idea that there is a selective pressure FOR homosexuality false because it is not directly tied to genes. This means Natural Selection could not "use" it to "better" the species by making it more "stable".

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If homosexuality cannot be shown to control population growth, what do we know DOES control population growth? Within other animals we know it to be things like disease (viruses, bacteria, parasites, etc), famine, and increased predation3. I see no reason to assume that humans are exempt from most of these and no evidence to conclude that we have evolved homosexuality as a method of population control, as again, current evidence shows homosexuality to be epegenetic in origin.

I imagine the author of the article thinks himself very progressive but what he is doing is actually harmful. The article seems to imply that homosexuality requires some sort of natural "utility" to make it "ok" or acceptable. This is just an extension of, or perhaps a reversal of, the Naturalistic Fallacy. It seems to be promoting the idea that if something is right or ok, it must be natural because what is natural is right, good, or ok. But if that is the only basis for why homosexuals must be treated with respect and not discriminated against then it rests on a very shaky foundation. If homosexuality is scientifically demonstrated to be a "side-effect" of a natural process, as it seems to be from recent research, then the idea that it is "natural" is eroded. If we as a society are going to make the choice that people should be respected and not discriminated against based on sexuality then we need to do so on real and not fallacious reasoning.

1 Supporting Claim that Homosexuals Conceive Children

Notice I am not claiming all homosexuals conceive children nor that homosexuals conceive children at the same rate as heterosexuals. This American Life: Double Lives

Gay man who fathered child for lesbians wins right to more access

Oscar Wilde, who is generally considered to have been a homosexual and not bisexual had two children. It strikes me as odd that people demanded a reference to this as the claim is, in my opinion, as easily verifiable as to be taken for granted since there have been so many instances of this throughout history.

2 Regarding the Exponential Growth of the World Human Population

In addition to the Wikipedia links given in the text, please see the UN's World Population Prospects site for the statistics regarding historical world population values and Human Population Growth for details regarding the mathematics for demonstrating that the world population has been growing exponentially for several centuries.

Robert Kaucher
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    The interesting question isn't anything to do with the *morality* of homosexuality, but with its evolutionary origin. How can something as superficially non-reproducing develop or persist given the normal rules of (crudely) the winner produces the most offspring? There are speculative theories. One argues that homosexual genes improve parenting (either via group-selection where groups with some homosexuals do a better collective job of parenting, or the genes for homosexuality confer better parenting skills on the non-homosexuals who carry them). – matt_black Jan 03 '13 at 16:20
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    @matt_black To clarify a point you clearly understand: It's not "speculative theory" that genes that improve overall population success may be selected for even if those genes leads to some individuals being less likely to breed (as any ant will attest). The "speculative theories" are that homosexuality may involve such genes. – Larry OBrien Jan 03 '13 at 19:36
  • The paragraph on morality was added simply as a further criticism of the article and does not directly pertain to the question asked. – Robert Kaucher Jan 03 '13 at 20:01
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    @Larry: That's slightly misleading. The successful genes aren't those that lead to overall population success (even at the expense of the individual). The successful genes are those that lead to THOSE genes having population success. The "faulty premise" being that the genes are trying to "preserve the species over the individual" rather than "preserve themselves over the individual". – Oddthinking Jan 03 '13 at 20:55
  • @Oddthinking Agreed. – Larry OBrien Jan 03 '13 at 21:08
  • "We know as a fact that homosexuals do conceive children." we do? People may *like* to have same-sex but still have other-sex for reproductive purposes. E.g. http://www.babymed.com/gay-and-lesbian-pregnancy – Sklivvz Jan 03 '13 at 21:40
  • @Sklivvz: I agree we need a reference rather than saying "We know as fact". Your reference appears to support the claim, so I am confused. Should we just edit it in? – Oddthinking May 20 '13 at 17:06
  • @Oddthinking Thank you for the comment as I had forgotten this answer and had intended to add some references. Although I would point out that my central claim that current evidence for the cause of homosexuality as epegentics was referenced. Are there any other claims that I should reference? – Robert Kaucher May 20 '13 at 18:49
  • I had misread the OP (sorry about that), I only meant to say we need references. – Sklivvz May 20 '13 at 18:54
  • Nice piece of reasoning, but also a clear case of original research and against the rules of the forum. – denten May 20 '13 at 23:18
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    @denten - Could you site the rule as I don't see anything in the FAQ that would lead me to believe that my answer is some how against the rules of the forum. If it your argument is valid, though, I will remove it. – Robert Kaucher May 21 '13 at 01:47
  • You might want to recheck that UN data. From what i'm seeing, the growth in the next 85 years or so is expected to *slow down*. (Between 2013 and 2050, they project an increase of about 2.4 billion people; between 2050 and 2100 -- a longer span of time -- they project only about 1.3 billion. – cHao Oct 22 '14 at 04:36
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I find this question quite frustrating. It is a complete train-wreck, despite the OP's claims that it is "one of the better ones I've seen". It has received way too many upvotes from the community, despite comments pointing out some of its flaws. The answers have pussy-footed around this. It is time to go for the jugular.

The claim makes no sense whatsoever. It isn't just wrong because of its false premises and non-sequiturs. It is meaningless.

I shall use an extended analogy to try to explain this. Imagine I made the claim that:

The addition of the preservatives of sugar and formaldehyde to fruit cake have indubitably worked to preserve the recipe over the years.

You would be flabbergasted. This fruit-cake claim is riddled with errors. So is the original claim.

Unclear Term

What does "preserve the recipe" mean? Does it mean keep the recipe unaltered? Does it mean ensuring the recipe exists in the future? Does it mean ensuring the recipe grows in popularity? Does it mean ensuring the popularity remains the same?

If it means keeping the recipe unaltered, then the act of altering it clearly doesn't preserve the recipe. Likewise, if "preserve the species" means keeping the relative distribution of genes in the gene pool the same, introducing a genetic change doesn't preserve the species. [No references. I'm arguing about (lack of) definitions here.]

Further, the fact that homosexuality appears in other related species [Example], shows that homosexuality doesn't somehow stop evolution from happening, in the same way having sugar in the recipe obviously hasn't worked to keep recipes the same, or there would only be one sugary cake. Instead, cake recipes keep changing, and fruit cake recipes keep changing - which is to say, new mutations appear, and the relative populations of the different recipes change. And species with homosexual behaviours keep evolving.

If it means ensuring the popularity/population remains the same, which is implied by "reduction in population growth", then the species is completely failing to be preserved. The population is growing, especially since the advent of homosexuality - i.e. the beginning of homo sapiens. [Ref] This weird argument defends a demonstrably false conclusion.

False Premise 1

Fruit cakes don't contain formaldehyde. [Reference: I just made the claim it up, and I really hope it isn't true.]

Homosexuality isn't a simple matter of genetics. Reference.

Using a purely genetic argument to discuss the advent of homosexuality is flawed.

False Premise 2

Even if fruit cakes did contain formaldehyde, it doesn't mean that it would act as a preservative in cakes. That would have to be shown empirically.

Even if homosexuality was pure genetics, it doesn't mean that there is a reduction in population growth. That would have to be shown, and is possibly wrong. [Ref: one possible counter-hypothesis: kin selection]

Mixing of Levels

Even if cakes did contain formaldehyde and formaldehyde was a cake preservative, there is a huge difference between preserving an individual cake and preserving a recipe. They are at different levels of abstraction.

The claim makes a similar (common) error of confusing how evolution works - the unit of evolution is the gene, not the species. Evolution works to preserve (i.e. increase the relative population of) the successful genes, even at the expense of the species. [Reference: The Selfish Gene] The suggestion that group selection might occur through natural selection is heavily disputed.

This error in levels is further explained by evolutionary expert, Richard Dawkins, in his video addressing a similar question: "Is Homosexuality Nature’s Population Control?"

Conclusion

There are several false premises in the claim, showing a lack of understanding of populations and the biology of homosexuality. There is fault logic in the claim showing a lack of understanding of evolution. There is no clear definitions of the terms, making the question meaningless.

I hope I have clearly demonstrated: both the original question and my invented analogous statement are fruit-cake claims, riddled with errors.

Oddthinking
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  • Please reference that "*Using a purely genetic argument to discuss the advent of homosexuality is flawed*" follows from "*Homosexuality isn't a simple matter of genetics*". A not being completely explained by B, doesn't imply to me that it's flawed to talk about the way that B affects A in isolation from other causes. It happens in science a lot. –  Nov 01 '13 at 17:00
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My answer would be no, but it is not clearly proved nor provable (I don't see how it could ever be proven). I wanted to take a different angle than the other answers and I hope it will help the readers to draw their own conclusions.

If there is a correlation between population control and homosexuality, there should also be a correlation between the homosxuality rate through the ages. Sadly, we were not there to poll the population in ancient times even though it is known that homosexuality was present and accepted in ancient Greece [1] for instance. However, we do have surveys from the early 50's when the world population was only 2.5 billions compared to today 7 billions. So, looking to the research papers, can we see a correlation?


The surveys in scientific literature

1948 [2] (World pop.: around 2.4 billions)
Had homosexual experience: 37%
More or less homosexual: 10%
Exclusively homosexual: 4%

1974 [3] (World pop.: around 4 billions)
Had homosexual experience: 27%
More or less homosexual: 7%
Exclusively homosexual: 2-3%

1977 [4] (World pop.: around 4.1 billions)
More or less homosexual: 3.1%
Exclusively homosexual: 1.3%

1989 [5] (World pop.: around 5.3 billions)
Had homosexual experience: 20.3%
More or less homosexual: 3.3%

1990 to 1995 [6-12] (World pop.: around 5.3-5.7billions)
Had homosexual experience: 9-20.8%
More or less homosexual: 2-9%
Exclusively homosexual: 1-4%

2002 [13] (World pop.: around 6.5billions)
Bisexual: 1.8% (including bisexual)
Exclusively homosexual: 2.3%
Other: 4%

2006-2008 [14] (World pop.: around 6.8billions)
Had homosexual experience: 4-6%
Exclusively homosexual: 2-4%

Considering the scientific surveys, if there is any correlation to make between homosexuality rate and population, it would be that it is decreasing as population grow. However, it is widely accepted that the decrease after early research by Alfred Kinsey is more related to wrong estimates in the first place [15]. Moreover, we can see that the rate vary a lot between different surveys reflecting inherent uncertainty of the sexual orientation.


Per country

We could also look into the census done by different countries to see if the densily populated ones show higher homosexuality rate. Warning! depending on the country, the statistics are more or less accurate.

Canada [16] - Density: 3.41/km^2 - Homosexuality rate: 1.1% - Bisexual: 0.9%
United States [17] - Density: 34.2/km^2 - LGBT rate: 3.4%
China [18] - Density: 139.6/km^2 - Homosexuality rate: 0.8-4%
United Kingdom [19] - Density: 255.6/km^2 - Homosexuality rate: 1.1% - Bisexual: 0.4%
French Republic [20] - Density: 116/km^2 - Homosexual couples: 0.6% (no data on homosexuality)
Norway [21] - Density: 255.6/km^2 - Not Hetero: 1.1% - Do not wish to answer: 5.9%


In conclusion, from the statistics, there does not seem to be any link between the popuplation number and density and the homosexuality rate. Therefore, it does seem to contradict the claim that homosexuality exist to control the population growth.


References

[1] Davidson, J. (2007). The Greeks and Greek love: a radical reappraisal of homosexuality in Ancient Greece. Weidenfeld & Nicolson.

[2] Kinsey, A., Pomeroy, W., and Martin, C. (1948). Sexual Behavior in the Human Male. Philadelphia: W.B. Saunders.

[3] Hunt, M. (1974). Sexual Behavior in the 1970's. New York: Dell.

[4] Pietropinto, A., and Simenauer, J. (1977). Beyond the Male Myth. New York: Times Books.

[5] Fay, R., Turner, C., Klassen, A., and Gagnon, J. (January 1989). Prevalence and patterns of same-gender sexual contact among men. Science 243, 338-348.

[6] Harry, J. (1990). A probability sample of gay males. Journal of Homosexuality 19(1), 89-104.

[7] Smith, T.W. (1991). Adult sexual behavior in 1989: Number of partners, frequency of intercourse and risk of AIDS. Family Planning Perspectives 23(3), 102-107.

[8] Janus, S., and Janus, C. (1993). The Janus Report on Sexual Behavior. New York: John Wiley & Sons.

[9] Billy, J., Tanfer, K., Grady, W., and Klepinger, D. (1993). The sexual behavior of men in the United States. Family Planning Perspectives 25(2), 52-60.

[10] Taylor, H. (1993). Number of gay men more than four times higher than the 1 percent reported in a recent survey. The Harris Poll #20. New York, NY: Louis Harris & Associates.

[11] Laumann, E., Gagnon, J.H., Michael, R.T., and Michaels, S. (1994). The Social Organization of Sexuality: Sexual Practices in the United States. Chicago: University of Chicago Press.

[12] Sell, R. L., Wells, J. A., and Wypij, D. (1995). The prevalence of homosexual behavior and attraction in the United States, the United Kingdom and France: Results of national population-based samples. Archives of Sexual Behavior 24(3), 235-248.

[13] Mosher WD, Chandra A, Jones J. Sexual behavior and selected health measures: Men and women 15–44 years of age, United States, 2002. Advance data from vital and health statistics; no 362. Hyattsville, MD: National Center for Health Statistics. 2005.

[14] Chandra A, Mosher WD, Copen C, Sionean C. (2011)Sexual behavior, sexual attraction, and sexual identity in the United States: Data from the 2006–2008 National Survey of Family Growth. National health statistics reports; no 36. Hyattsville, MD: National Center for Health Statistics.

[15] McWhirter, D., Sanders, S., and Reinisch, J. (Eds.). (1990). Homosexuality/Heterosexuality. The Kinsey Institute Series. New York: Oxford University Press.

[16] http://www42.statcan.gc.ca/smr08/2011/smr08_158_2011-eng.htm

[17] Gates, Gary J.; Newport, Frank (October 18, 2012). "Special Report: 3.4% of U.S. Adults Identify as LGBT".

[18] http://www.chinadaily.com.cn/english/doc/2004-12/02/content_396559.htm

[19] http://www.ons.gov.uk/ons/rel/integrated-household-survey/integrated-household-survey/april-2011-to-march-2012/stb-integrated-household-survey-april-2011-to-march-2012.html

[20] http://www.insee.fr/fr/themes/document.asp?ref_id=ip1435

[21] http://www.ssb.no/a/english/publikasjoner/pdf/rapp_201038_en/rapp_201038_en.pdf

Zonata
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    An excellent answer. – Robert Kaucher May 21 '13 at 01:41
  • (1) These survey comparisons across time and across countries probably tell us more about the societies and their taboos and the assumptions made in the surveys than it does about the base-rate of same-sex attraction. (2) you haven't shown a lack of causality. Has decreased prevalence *lead* to population growth? (No, but you haven't shown that.) – Oddthinking May 21 '13 at 04:49
  • @Oddthinking (1) How would you expect one to obtain a more accurate portrait of homosexuality than looking through the scientific literature? (2) I have shown there is no link between both. Some time population have grown and the rate increase and other time it is the contrary. What more would you need to be convinced? Some scientist drawing the conclusion for you and writing it in a paper? Moreover, OP claims said "obvious reduction in population growth"... not the opposite. – Zonata May 21 '13 at 05:09
  • @Zonata: We need to accept that sometimes the scientific literature does not or cannot answer a question. You may have the best possible historical data available AND cannot draw conclusions because of the size of the unknowns. (I am trying to remember the name of this logical fallacy for further reading, but I am drawing a blank.) – Oddthinking May 21 '13 at 05:12
  • @Oddthinking Yes, and I do agree with that. But what kind of answer would be good for such question? If the matter is not provable than is the question really pertinent? As a skeptic, I always seek for the most plausible answer given by the scientific literature. So, no, it is not a proof, but it is as close as we can get. – Zonata May 21 '13 at 05:16
  • (2) I was convinced by the arguments about gene-selection over group-selection. Yes, it was a scientist drawing the conclusion and writing it down (probably the Dawkins in The Selfish Gene, but I don't recall.) I was convinced by the arguments that the population growth has continued to happen, making the idea that homosexuality works to prevent population growth moot. – Oddthinking May 21 '13 at 05:20
  • I do believe that @Zonata adds to the discussion by pointing out what we would expect to see if the question's premise were true. – Robert Kaucher May 21 '13 at 13:59
  • Please provide a reference for "If there is a correlation between population control and homosexuality, there should also be a correlation between the homosxuality rate through the ages." –  May 21 '13 at 16:05
  • There are no such scientific paper proving that, since it is trivial. Neither there is any scientific paper answering directly the question (first, scientist community would need to prove homosexuality as genetic, which is far from done). Maybe you could give me a better explanation of what you are expecting...? – Zonata May 21 '13 at 16:47
  • It isn't trivial. Why would population control be correlated with "the ages"? You need to justify the leap from "correlation between population control and homosexuality" and "correlation between homosexuality rate through the ages". It seems that you assume that population control will increase noticeably due to the population growth that we've experienced. That needs a reference. –  May 24 '13 at 07:18