I think I'm Gay

Viking, I am SO Proud of you for trying to cite scientific evidence! :woo hoo: Keep up the good work!

Unfortunately, that study is total crap.
http://www.boxturtlebulletin.com/tag/walter-r-schumm

To perform a meta-analysis, a researcher collects a bunch of other studies and combines all of the data from their samples, re-crunches the data, and sees which trends hold up in the much larger sample. These kinds of studies can be useful in identifying trends and correlations, but they cannot be used to extrapolate behaviors or conditions to the population as a whole.

But Schumm’s “meta-analysis” (and Cameron’s before him) doesn’t even have the benefit of being built off of random convenience samples. There were no convenience samples in any of the ten prior works that Schumm used for his meta-analysis. In fact, they weren’t even professional studies. They were popular books! This is utter nonsense. None of the books contained any semblance of a sample — not even a convenience sample, and the authors certainly didn’t do anything approaching an ”important data collection” by any stretch of the imagination.

That is how good stories are gathered, but it most certainly is not how a sample is collected for statistical purposes. To run statistics on this non-statistical (or anti-statistical) sample would be like judging the ratio of giraffes to chimpanzees in Africa by comparing the populations selected by the zookeepers at your local zoo. Whenever a non-random selection process is used, any attempt at statistics on that process is completely meaningless — and an abuse.

The best source to find primary publications is NCBI's National Library. [url=http://www.ncbi.nlm.nih.gov" onclick="window.open(this.href);return false;]http://www.ncbi.nlm.nih.gov[/url] Select PubMed under Search criteria, type in key words, and you'll get back any scientific article that has been published that contains those keywords. You'll get lots of extra stuff that doesn't pertain (like when I typed in "homosexuality genetic") I got back lots of studies on HIV infection rates - those don't tell me about genetic factors of homosexuality, just how genetic factors affect HIV infection rates; you have to separate the wheat from the chaff. The best place to start is with Reviews - articles that have performed a review of the current literature available and done the analysis for you; they are also generally much easier to read than primary research articles as they don't contain much jargon or very detailed study methods. They do list all the publications that they reviewed so you can go delve more deeply as you like.
http://www.ncbi.nlm.nih.gov/pubmed/19961060
[Influence of genetic factors on human sexual orientation. Review]
Invest Clin. 2009 Sep;50(3):377-91.
Abstract

Human sexual orientation is a complex trait, influenced by several genes, experiential and sociocultural factors. These elements interact and produce a typical pattern of sexual orientation towards the opposite sex. Some exceptions exist, like bisexuality and homosexuality, which seem to be more frequent in males than females. Traditional methods for the genetic study of behavior multifactorial characteristics consist in detecting the presence of familial aggregation. In order to identify the importance of genetic and environmental factors in this aggregation, the concordance of the trait for monozygotic and dizygotic twins and for adopted sibs, reared together and apart, is compared. These types of studies have shown that familial aggregation is stronger for male than for female homosexuality. Based on the threshold method for multifactorial traits, and varying the frequency of homosexuality in the population between 4 and 10%, heritability estimates between 0.27 and 0.76 have been obtained. In 1993, linkage between homosexuality and chromosomal region Xq28 based on molecular approaches was reported. Nevertheless, this was not confirmed in later studies. Recently, a wide search of the genome has given significant or close to significant linkage values with regions 7q36, 8p12 and 10q26, which need to be studied more closely. Deviation in the proportion of X chromosome inactivation in mothers of homosexuals seems to favor the presence of genes related with sexual orientation in this chromosome. There is still much to be known about the genetics of human homosexuality.

We have 23 pairs of chromosomes, all are separately identifiable by their size and the genes contained therein - so your chromosome 12 is the same as my chromosome 12. Chromosomes are further identified by their "center" - an area where there are no genes because it is the attachment point for proteins to split apart duplicated chromosomes when the cell is dividing. One side of the chromosome is identified as "p" and the other as "q", and further subdivided into regions based on "staining bands" - the stripes that show up on chromosomes when stained with a special dye. Hence, in the abstract above, when gene regions 7q36 or 8p12 are mentioned - these are identifiable, narrowed regions, often thousands of base pairs long containing many genes.

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Multifactorial genetic studies are very difficult and take much time - the effects of any single gene will be very small and make it hard to exactly pinpoint, with statistical probability, that it definitely causes, or prevent, its phenotype (the expressed physical trait, in this case, homosexuality). There will not ever be a single "gay" gene found - this is a complex multifactorial trait, meaning affected by many genes working in concert, both for and against each other. So while there has not been any specific gene identified to date, there are regions that strongly associate with homosexuality and the research is ongoing to isolate which genes and how they would interact to create such a behavior. Will people who grow up in gay households be more likely to be gay, very likely. But because they grow up in an environment that is more tolerant, open-minded, and accepting of everyone, not just because they think they want to be more like their Mommies or Daddies. Homosexuality is both a genetic and environmentally-based behavior, just like almost all others, not to be condemned or applauded. It. Just. Is.



More studies:
http://www.ncbi.nlm.nih.gov/pubmed/18536986
Genetic and environmental effects on same-sex sexual behavior: a population study of twins in Sweden.
Arch Sex Behav. 2010 Feb;39(1):75-80. Epub 2008 Jun 7

There is still uncertainty about the relative importance of genes and environments on human sexual orientation. We used data from a truly population-based 2005-2006 survey of all adult twins (20-47 years) in Sweden to conduct the largest twin study of same-sex sexual behavior attempted so far. We performed biometric modeling with data on any and total number of lifetime same-sex sexual partners, respectively. The analyses were conducted separately by sex. Twin resemblance was moderate for the 3,826 studied monozygotic and dizygotic same-sex twin pairs. Biometric modeling revealed that, in men, genetic effects explained .34-.39 of the variance, the shared environment .00, and the individual-specific environment .61-.66 of the variance. Corresponding estimates among women were .18-.19 for genetic factors, .16-.17 for shared environmental, and 64-.66 for unique environmental factors. Although wide confidence intervals suggest cautious interpretation, the results are consistent with moderate, primarily genetic, familial effects, and moderate to large effects of the nonshared environment (social and biological) on same-sex sexual behavior.

http://www.ncbi.nlm.nih.gov/pubmed/18074215
Eye color, hair color, blood type, and the rhesus factor: exploring possible genetic links to sexual orientation.
Arch Sex Behav. 2008 Feb;37(1):145-9.

The present study sought to expand the limited evidence that sexual orientation is influenced by genetic factors. This was accomplished by seeking statistical differences between heterosexuals and homosexuals for four traits that are known to be genetically determined: eye color, natural hair color, blood type, and the Rhesus factor. Using a sample of over 7,000 U.S. and Canadian college students supplemented with additional homosexual subjects obtained through internet contacts, we found no significant differences between heterosexuals and homosexuals regarding eye color or hair color. In the case of blood type and the Rh factor, however, interesting patterns emerged. Heterosexual males and females exhibited statistically identical frequencies of the A blood type, while gay men exhibited a relatively low incidence and lesbians had a relatively high incidence (p < .05). In the case of the Rh factor, unusually high proportions of homosexuals of both sexes were Rh- when compared to heterosexuals (p < .06). The findings suggest that a connection may exist between sexual orientation and genes both on chromosome 9 (where blood type is determined) and on chromosome 1 (where the Rh factor is regulated).

http://www.ncbi.nlm.nih.gov/pubmed/16369763
Extreme skewing of X chromosome inactivation in mothers of homosexual men.
Hum Genet. 2006 Feb;118(6):691-4. Epub 2005 Dec 21.

Human sexual preference is a sexually dimorphic trait with a substantial genetic component. Linkage of male sexual orientation to markers on the X chromosome has been reported in some families. Here, we measured X chromosome inactivation ratios in 97 mothers of homosexual men and 103 age-matched control women without gay sons. The number of women with extreme skewing of X-inactivation was significantly higher in mothers of gay men (13/97=13%) compared to controls (4/103=4%) and increased in mothers with two or more gay sons (10/44=23%). Our findings support a role for the X chromosome in regulating sexual orientation in a subgroup of gay men.

http://www.ncbi.nlm.nih.gov/pubmed/15724806
Sexual differentiation of the human brain: relevance for gender identity, transsexualism and sexual orientation.
Gynecol Endocrinol. 2004 Dec;19(6):301-12.

Male sexual differentiation of the brain and behavior are thought, on the basis of experiments in rodents, to be caused by androgens, following conversion to estrogens. However, observations in human subjects with genetic and other disorders show that direct effects of testosterone on the developing fetal brain are of major importance for the development of male gender identity and male heterosexual orientation. Solid evidence for the importance of postnatal social factors is lacking. In the human brain, structural diferences have been described that seem to be related to gender identity and sexual orientation.

I'm gonna stop here so I don't overload y'all. This is through Result #80 if 322 when I searched PubMed for Homosexuality genetics. Feel free to do the search yourself if you want to learn more! You can also try homosexuality environment, or any other variation thereof to see what's been found on that side of the coin.

The Viking wrote: Too much to read right now. Are you saying there is genetic proof that there is a 'gay' gene?

Great seeing you at lunch the other day by the way. Michelle really liked you.

Good seeing you too. I really liked Michelle as well (tell her I said Hi!) - would like to get to know her better and figure out what she see in you! :jk2: You two are cute together!

Back on topic: proof is a pretty strong word that I wouldn't use just yet on this subject. There is strong evidence that there are multiple genes, not one only, that added together equal a genetic predisposition towards homosexuality. Multifactorial means more than one gene creating the physical characteristic; so each gene itself has a very small effect (and it can be as few as ten or as many as hundreds that work together for this trait, that's a loonnnnggg way off knowing). As homosexuality is not a 50-50 occurance in our population, then those genes' effects are obviously not that dominant in the first place, also making them hard to identify.

If a person has some but not all of those genes that favor homosexuality, then environment will play more of a role in determining their lifestyle, but if they have all of the genes that confers homosexuality then they will be gay no matter what. For example, there is evidence of environmental factors, like androgen exposure in the womb, that leads to differing neural patterns in homosexuals. But environmental factors also must work in the background of a person's genetic make-up - androgen sensitivity may be conferred by the strength or weakness of the androgen receptor made by that person's Androgen-Receptor gene so that not every female who is exposed to higher levels of androgens will become gay. Does that make sense? I'm not sure how else to explain it, other than by getting really, really technical. Absolutely environment plays a big part in it, and that's never been denied by biologists or gay proponents. Comparing genetic disposition toward homosexuality to that of alcoholism or addiction is similar (there are definite genetic and environmental factors which are better understood), but I myself wouldn't compare them too closely because homo- or heterosexuality isn't a disease state like alcoholism or addiction.

rt- there's a difference between aborting for Down's Syndrome and homosexuality - Down's Syndrome can be positively and absolutely identified by the physical characteristics presented in the womb. Homosexuality, even once all genes that confer a predisposition to homosexuality are identified, which is decades out, is not an absolute that the baby will become homosexual as they environmental factors are just as strong as the genetic factors, if not a little stronger. Down's Syndrome is a 100% genetic caused disease - no environmental factors involved. So if we don't improve our tolerance of gays in the next several decades, which is not the way the movement is trending, and a parent is presented with evidence that suggests that their child may become gay, then they'd be idiots to abort their child on such 'Ifs". But that's just me.