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Homosexaulism: genes and environment


Luiz Henning

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Introduction:

There is a recurring debate about homosexuality - whether it is an accepted biological genetic cause - or whether it is a "moral deviation" caused by the social environment. In this topic, I come to argue that, although homosexuality does have a genetic basis, it seems to be largely environmental

NOTE: I do not believe that homosexuality is a "moral deviation" and it is far from that, but it seems to be largely influenced by the environment without a doubt.   

Genetic cause: 

Much like any other trait, homosexuality is a result of genes and the environment. One way to estimate the influence of biology is to use something called twin studies. To do a twin study, researchers get MZ twins, who share 100% of their genes, and DZ twins who only share 50% of their genes. If both members of the MZ twins exhibit the same trait, then one can infer that genetics plays a role in this. If they differ, than the environment may play a large role than genes. When it comes to homosexuality, twin studies have been done to estimate the effects of genetics and environment on someone being gay.

The first paper that has been published on this comes from Kallmann (1). In looking at 85 twins, Kallmann found a 100% concordance rate between twins, meaning that homosexuality was 100% genetic. In 1999, Edward Stein criticized the Kallmann study for not showing any evidence that his twin sample was genetically identical, and for using an unrepresentative sample. Kallmann’s sample was drawn from psychiatric patients, prisoners, and others (2). Instead of Kallmann’s sampling technique being random, it was instead a convenience sample that doesn’t allow for generalizations. Although Kallmann’s study was flawed, better studies attempting to measure the heritability of homosexuality were released years later.  

Bailey et al. (3) looked at 4,901 twins from the Australian National Health and Medical Research Council Twin Registry, which had a large probability sample which is more representative. Homosexuality was measured through the Kinsey Scale, a questionnaire that measures homosexual tendencies. According to the authors, the heritability of homosexuality was 0.45 for men and 0.8 for women. Shared environment explained 0% of the variance in men, but it explained 0.41% of the variance in women. Nonshared environment was more equal across men and women, with nonshared environment explaining .55% of the variance in men and .50% in women. This means that when it comes to the genetic influence of homosexuality, it was more genetic for men than for women. Homosexuality was more environmental for women, but more genetic for men. Considering the wide CIs, it’s hard to know how reliable their estimates are. Kirk et al. (4) used a sample from the Australian NHMRC Twin Registry, and found the heritability of homosexuality to be 0.35-.40 for men but not for women. The effects of genes weren’t insignificant, but the environment still played a larger role than genes.

Still in 2010. Långström et al. (5) looked at 3,826 MZ twins and DZ twins from the Swedish Twin Registry. To measure homosexuality, the researchers used the STAGE questionnaire which measures lifetime same-sex partners. The heritability for at least having one lifetime same-sex partner was 0.39 for men and 0.19 for women. Shared environment explained none of the variance in men but 0.17 in women. Non-shared environment explained 0.61 of the variance in men and 0.64 in women. For total number of same-sex partners, the heritability was 0.34 for men and 0.18 for women. Shared environment explained non of the variation in men but 0.16 of the variation in women; non-shared environment was the same for both men and women at 0.66. Like the last study, homosexuality was more genetic for men and more environment for women. Although, the heritability for men was 0.39 and 0.34, so the environment still played a large role for both sexes.

Bearman and Bruckner (6) looked at data from the NLSY, with their sample size being 18,841. When looking at the genetic influence, they did not find significant evidence. Identical twins were 6.7% concordant, DZ twins were 7.2% concordant, and full siblings were 5.5% concordant. It was concluded that a genetic influence, if present, can only be expressed in specific social structures. The authors did find support that “less gendered socialization in early childhood and preadolescence shapes subsequent same-sex romantic preferences.” Although this study suggests almost no genetic influence on same-sex attraction, more research is needed to support this. In contrast to the studies noted above, Kendler et al. (7) looked at 2,174 people (794 twin pairs and 1,380 non-twin siblings) and measured same-sex attraction through a single item questionnaire. The authors suggests the genetics provide an important influence on same-sex attraction, but caution should be taken when looking at their results because of low statistical power. Only 19/324 identical twin pairs had a non-heterosexual member, with 6/19 pairs being concordant. 15/240 same-sex fraternal twins had any non-sexual members, and only 2/15 of the pairs were concordant. Because of these issues, it’s hard to draw any conclusions from this study.

 

Another way to estimate the effects of genes on a trait come from GWAS. In this method, researchers get some genes that correlate with a trait, and see their estimated effect. One study like this has been done on homosexuality, but the media talk surrounding it seems to be misinterpreting how genes for traits work. When it comes to the genotypic influence on a trait, almost all traits are polygenic. All this means is that multiple genes are responsible for a trait rather a single gene. Although this is well known, it hasn’t stopped some people in political circles from showing this as evidence that “no single gene is responsible for homosexuality”, even though this doesn’t mean that genes do not have an effect on homosexuality. Ganna et al. (8) analyzed genome data from 477,522 individuals in the U.K and United States, with a replication in the U.S. and Sweden with 15,142 people. In all their genetic variants tested, they explained 8%-25% of the variance, a number substantially smaller that what twin studies give. These results should not be used to show that twin studies are wrong, rather than of the known genes known to correlate with homosexuality, they explain a small percent of the variance. Even then, the genes used have to have a certain effect size; meaning that other genes which may influence homosexuality that have smaller effects are being left out, leaving the heritability estimate as an underestimate.

In conclusion, the genetic cause seems to vary between men and women, the genetic cause is not insignificant, but for both sexes, the environment is a major watershed when it comes to this issue. In all, the heritability of homosexuality for men appears to be <0.45-0.50, and for women the estimate is much lower. For women, the environmental influence is> 0.50 and for men it is the same - just about a few 0.Xs. The effects of genes are homosexuality are not insignificant, but the environment certainly outweighs the effects of genes. GWAS gives lower estimates due to its nature, so we should not rely on its results for the time being.

Possible environmental causes:

We know, then, from previous information, that homosexuality can be largely environmental. I cannot speak of all environmental causes with 100% clarity, but I can point out some, two to be more precise, which seem to be much more connected to this.

Child Abuse: Looking at 1,001 adult homosexual and bisexual men who attended STD clinics from May 1989 to 1990, Doll et al. (9) found that 37% of participants reported that they were encouraged or forced to have sexual contact with an older or more powerful partner before age 19; 94% of these cases occurred in men. The average age of the participants' first contact age was only 10 years. Of the cases examined, 51% involved the use of force and 33% involved anal sex. Harry (10) analyzed 17 gay men and 67 heterosexual males from a large midwestern university, with questionnaires given to gays from the local LG student organization. A subsample was created so that the distribution of heterosexual students corresponded to that of gay students in the classes. Using a Pearson correlation, homosexuals reported a significantly higher rate of physical abuse from their parents than their heterosexual peers. Runtz and Briere (11) used a questionnaire with 278 female undergraduate students to assess the effects of child abuse. Not only were those who were abused as children more likely to express more negative behaviors, but they were also more likely to have "homosexual contact". Referencing, 2 previous studies - with one finding a positive connection and the other finding no connection, the authors suggest that more research is needed on this subject. But we can already have a good basis for such a statement, and perhaps a possible environmental cause. In general, it probably suggests that there is a small association between homosexuality and child abuse, but more factors probably explain why some people become gay. And perhaps the evidence of the strongest environmental cause is the one I am going to address now.

Food hypothesis: One of the environmental causes that can be determinant in the cause of homosexuality today is the food cause. It is known that what differentiates the functioning of the male and female brain (and, consequently, the heterosexual / homosexual brain) is the amount of sex hormones that is absorbed by the brain from pregnancy until close to the beginning of puberty. Industrialized foods and treated water from various locations have a hormone called Xenoestrogen, and it is proven that this hormone can cause hormonal disruptions to individuals who ingest it in excess. So if pregnant women and those born up to 4 years old (age at which the human brain is under-matured) consume many foods "rich" in Xenoestrogen, one can deregulate the "normal" production of hormones typical of the sexes. In my opinion, this is the best hypothesis about the cause of the increase in homosexuality. They recommend that you read the book "The Stolen Future" (Theo Colborn, Dianne Dumanoski and John Peterson)  which explains this hypothesis better, including showing experiments with oxen, dogs, crocodiles and mice. (12

Conclusions:

Homosexuality has a genetic basis, but it appears to be largely environmental, rather than genetic. 

 

 

 

 

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OK.
There is a genetic element, a hormonal element and an environmental element.
Possibly all three in varying combinations.

I don't think anyone has ever argued for a totally genetic basis.

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4 minutes ago, MigL said:

OK.
There is a genetic element, a hormonal element and an environmental element.
Possibly all three in varying combinations.

I don't think anyone has ever argued for a totally genetic basis.

I made this topic more like a criticism of people who think that homosexuality is strictly genetic or hereditary. Some even come up with chaotic statements like the so-called "gay genes"

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59 minutes ago, Luiz Henning said:

I made this topic more like a criticism of people who think that homosexuality is strictly genetic or hereditary. Some even come up with chaotic statements like the so-called "gay genes"

You acknowledge that there is a genetic element that contributes to homosexuality. If there is such an element surely that can only be the existence of one or more genes that, through their expression, predispose people to homosexual practice. So, why are you decrying such claims?

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I have a perspective on homosexuality and trans folk which has a more anti-social implications from the world of psychology.  When you get deep into the study of anti-social behaviors, they all become linked by a rebellion.  A rebellion against outside rules and norms, and it even becomes a rebellion against their own brains and emotions.  They simply refuse to be controlled by any system, even their own emotions and the emotions of others.  This is in deep cases of anti-social disorders.  The disorder literally rearranges how the person feels pleasure or non-pleasure.  This is the very nature of anti social personality disorder.  Homosexuality is also based in how the person feels about the sexes, and a disorder could rearrange how they see pleasure in the different sexes.  An anti-social wants their objectivity to be the highest objectivity, so in denying that, as an anti-social, a male can turn his natural drive to be attracted to women, into his own pleasure hunt to deny the power of the natural drive.  Seeking power over the things that wish to control our decisions, is an oft used human behavior.

So, an male anti-social person could feel like society, or their environment is pushing them to desire women.  To feel free from this push and to have power over it, the person could decide to be attracted to men and male characteristics.  That is how anti-social behaviors work, when applied to homosexuality.  

It could also easily be seen as sexual narcissism.  A sexual narcissist would be aroused by their own bodies. And if a man is a sexual narcissist, he may seek what he is, in others.  If you examine the gay community, you find different segments within it.  SM, Muscle, leather, feminized, etc.  They often do not inter-date, and even have their own social events.  This really gives homosexuality the look and model of different approaches to solve the same issue.  Most of those approaches could be seen as disordered, even the hormonal or gene driven ones.  A disorder in the genes or hormone process, may create disorders brains.  Isnt that the point?  

What we need to do is remove the stigma from the word disordered.  I have yet to meet one single person without some type of behavioral disorder, and I'm sure that means, I have yet to meet anyone with a perfect system, brain, genes and hormones.   But subjective solutions and reactions to the models we encounter (heterosexuality), that simply do not appeal to us, for whatever reason, may be replaced by our own subjective solutions (homosexuality) that take offense with being directed.  Because a subjective solution is not truly subjective, without a perspective.  And a person who is very aware of control, is aware of that.  

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2 hours ago, Area54 said:

You acknowledge that there is a genetic element that contributes to homosexuality. If there is such an element surely that can only be the existence of one or more genes that, through their expression, predispose people to homosexual practice. So, why are you decrying such claims?

I believe that two things happened here

1) did not understand my text

2) or I expressed myself poorly

Anyway, what I say, briefly, was: Homosexuality is largely influenced by the environment, despite having a genetic basis, genetics is not a good explanation at that time. That is why I criticize people who think that Homosexuality is 100% or largely influenced by genetics / Biology, disregarding major factors such as the food hypothesis I mentioned. There are many more things in the family / social environment that influence this, than genetic things themselves.

2 hours ago, JohnSSM said:

I have a perspective on homosexuality and trans folk which has a more anti-social implications from the world of psychology.  When you get deep into the study of anti-social behaviors, they all become linked by a rebellion.  A rebellion against outside rules and norms, and it even becomes a rebellion against their own brains and emotions.  They simply refuse to be controlled by any system, even their own emotions and the emotions of others.  This is in deep cases of anti-social disorders.  The disorder literally rearranges how the person feels pleasure or non-pleasure.  This is the very nature of anti social personality disorder.  Homosexuality is also based in how the person feels about the sexes, and a disorder could rearrange how they see pleasure in the different sexes.  An anti-social wants their objectivity to be the highest objectivity, so in denying that, as an anti-social, a male can turn his natural drive to be attracted to women, into his own pleasure hunt to deny the power of the natural drive.  Seeking power over the things that wish to control our decisions, is an oft used human behavior.

Beautiful reflections. And they make total sense, I had never looked at that perspective. Thank you very much.

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4 minutes ago, iNow said:

Or, some people just prefer chocolate while others prefer vanilla. Rebellion and antisocial behavior neither required nor parsimonious. 

I hate to be the voice of disagreement, but even biases towards flavors will be influenced by the environment and genes.  Or is there another factor that contributes to our consciousness and how we perceive the outer world? Outside our Markov blanket, obviously.  Maybe the spirit, or the soul.  Or maybe you just believe there is any part of you that i'snt a factor of genes and environment.   But taste?  I highly doubt it.  Every human behavior and experience and opinion is formed in the same way.  That doesnt mean you actually had any control over it.  A schizophrenic may think chocolate and vanilla and monsters.   Its the same as you thinking one tastes better than the other.

Edited by JohnSSM
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2 minutes ago, JohnSSM said:

When you figure out exactly what might be lacking in the brain structure of homosexuals

Comments like these remind us of how very far we still need to go as a society when discussing topics like homosexuality.

There is nothing lacking in the brains or brain structures of nonheterosexual humans. They simply prefer other humans with similar plumbing. On a related note, there’s nothing lacking in the brains of people who prefer cats over dogs. Hard to believe, I know, but true  

Comments like yours quoted above, however, do suggest a lack in the posters brain, or at least in their empathy and decency. 

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11 minutes ago, Luiz Henning said:

Beautiful reflections. And they make total sense, I had never looked at that perspective. Thank you very much.

Thank you!  But hopefully they are not only pleasing, but truthful approaches.  Its so nice that someone understands my words and doesnt accuse me of being a whacko or uneducated.   Im writting a book on this subject, which covers universal behavior.  Its hard some some folks to grasp it.

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11 minutes ago, JohnSSM said:

I hate to be the voice of disagreement, but even biases towards flavors will be influenced by the environment and genes. 

Of course, but I obviously was commenting on your suggestion that they were influenced by desire for rebellion and antisocial behavior. I’m in 100% agreement that flavor preferences are a result of both genetics and experience.

Is this another example of your problems with reading comprehension? 

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Just now, iNow said:

Comments like these remind us of how very far we still need to go as a society when discussing topics like homosexuality.

There is nothing lacking in the brains or brain structures of nonheterosexual humans. They simply prefer other humans with similar plumbing. On a related note, there’s nothing lacking in the brains of people who prefer cats over dogs. Hard to believe, I know, but true  

Comments like yours quoted above, however, do suggest a lack in the posters brain, or at least in their empathy and decency. 

What would you tell anyone with disordered behavior?  DO you want to make them feel like they aren't disordered, or do you want to explain the behavior?  I would rather find the model that most closely accounts for the behaviors, created from the mechanisms we know already work to drive many disorders.  Politically correct. When psychology is politically correct, all sex becomes sex positive, and all sex is not positive.  Sex addiction drives people to disordered behaviors as much as meth addiction.  So is all sex positive?  No...so we are going to have to tell some people they have disorders.  Which is why I said we need to destigmatize all disorders to make them all equal and accepted to ordered behavior.  That doesnt mean we have to stop searching for the reasons they exist honesttly.

Why did i have to explain that to you?  Are you being purposefully obtuse in order to hijack this thread, or you understand nothing of what is being discussed, again.

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1 minute ago, JohnSSM said:

What would you tell anyone with disordered behavior? 

Depends on the disorder and my relationship to them, but to reiterate my actual point: homosexuality isn’t a disorder so your reply is moot. 

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4 minutes ago, iNow said:

Depends on the disorder and my relationship to them, but to reiterate my actual point: homosexuality isn’t a disorder so your reply is moot. 

Do you detect any natural order in sex between opposite sexes?  Think long and hard.  IF you dont see any natural order to sex between opposite sexes, in this evolutionary world, you have missed he point allready.  Disorder is not a put down.  It is a fact of the universe.  We all have it, get over it.  I love gay people.  Their sexual personality disorders means nothing to me, so I dont judge them at all.  Disordered and perfect.  Thats the difference between the reality of homosexuality, and my equilibrium with it.  I am fine with it.

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Just now, JohnSSM said:

Their sexual personality disorders means nothing to me, so I dont judge them at all.

Labeling two people who love each other as “disordered” due solely to their plumbing is, in fact, a judgment, and this will remain true regardless of how forcefully or consistently or condescendingly you protest. 

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Just now, iNow said:

Labeling two people who love each other as “disordered” due solely to their plumbing is, in fact, a judgment, and this will remain true regardless of how forcefully or consistently or condescendingly you protest. 

Which definition of love are you using?  There are so many, with no objective view of it anywhere in any official and agreed to document. Do you know how many version of love the ancient greeks had?  Which one shall I use?

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A masochist may never back down, no matter how much they are proved wrong, and put on the spot.  Its considered anti-social behavior because it never leads to any pro-social results.  It's also supposed to feel bad, but they can ignore those feelings, to stay in apparent control. Yknow, people who wont agree that man made industry is probably warming the climate to some degree.  Itll be very anti social when the atmosphere loses it's ability to support life.

You believe you are being the sadist, you feel powerful, as you question and discuss a topic which I understand much better than you.  But you dont have the power, or the knowledge, or the perspective to be in control of the understanding of this topic.  That is why I am guiding it and you are flailing around subjects, never addressing the OP.  Thread hihacking.  But it's really an anti-social drive used to oppose things we dont like.  What have I done to make you dislike me so much, and believe I dont have years of experience and knowledge in this field, that you may not have?  

1 minute ago, iNow said:

Irrelevant. Changing the definition of love has zero impact to either the veracity or validity of my challenge.

Homosexuality is not disordered. Calling it disordered is a judgement.

The love of another mans body is the same as the love for another mans personality? Did you love your father?  Did you want to have sex with him?  Jeez.  Love has many definitions and perspectives.  Im sorry its not a black and white subject, but can you take your frustrations out elsewhere?

May I suggest a subject which can be seen in black and white.  Like math?  I dont really think you believe love can be more than one thing, but since it is subjective, it is never any one thing.  I dont think you like that reality and you dont seem to work well within those borderless views of understandings on many levels beyond black and white.  BUt all you do is mock them.  Thats how people act when they dont like something.  Do you think it represents a disordered behavior that many people use?   I know it is.

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4 minutes ago, JohnSSM said:

Love has many definitions and perspectives

Agreed, and yet this has literally nothing to do with my point.

At this point, I can no longer give you the benefit of the doubt and assume you have severe reading comprehension problems. You’re obviously arguing in bad faith. 

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Just now, iNow said:

Agreed, and yet this has literally nothing to do with my point.

At this point, I can no longer give you the benefit of the doubt and assume you have severe reading comprehension problems. You’re obviously arguing in bad faith.

Yes, I do have bad faith in you.  You never addressed any issues you had with the OP that I didn't dismiss with proof.   It has shown me that you are not an expert of psychology to the degree that I am, and you obviously assume you are.  But you dont have the working knowledge and understanding to comprehend the points I make, and you mock them.  Im sick of it, but Im learning so much about how to handle people.

I have had no difficulty in reading.  But i've pointed out plenty of difficulties you have understanding psychology.

Its like me saying to you..."Its an example of free energy dude"...and you go, "which kind?".  You arent being unkind, I am uneducated in seeing all the expressions of free energy. 

I am not uneducated in how to see love.  That's what I study.  You thought it could be seen as a single thing in psychology?  An expert on love would know.

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PS, if the tendency to disorder builds upon itself as entropy grows, what does that say about the future of homosexual percentages in our society?  They are going up, and they will go up everywhere as humans evolve in a fight with natural order.  But that's only if you understand entropy and disorder and have experience transformation the model into psychology and future's prediction

Just now, Luiz Henning said:

I would like to have some basic knowledge of psychology, however, unfortunately I do not, so I prefer to abstain only from the Genetic / Biological part of the thing.

Oh jeez, I have gaslighted your topic.  I am really sorry.  This other guy followed me wherever I go to start arguments.  Thanks for allowing me to do this!  Great subject!  Good luck with your explorations!

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Just now, JohnSSM said:

Oh jeez, I have gaslighted your topic.  I am really sorry.  This other guy followed me wherever I go to start arguments.  Thanks for allowing me to do this!  Great subject!  Good luck with your explorations!

No problem, I'm just sad to know that I couldn't contribute to this debate on psychology and homosexuality, it seems to be very interesting.

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3 minutes ago, Luiz Henning said:

No problem, I'm just sad to know that I couldn't contribute to this debate on psychology and homosexuality, it seems to be very interesting.

If you ever want to discuss how the goals of each personality disorder are driven by genes which guide the structure of the brain which creates the behaviors, theorizing how genes may use the same approach to learning, or what we call evolution, when it comes to making genetic changes in the brain, as different environments can expose humans to different ways of solving solutions, could this same drive be true of the genes that have constructed our brains and our bodies....let me know...ha...I could go on for many hours.

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55 minutes ago, JohnSSM said:

I am not uneducated in how to see love.  That's what I study

Lol. Still absolutely unrelated to my actual point.
 

1 hour ago, iNow said:

Changing the definition of love has zero impact to either the veracity or validity of my challenge.

Homosexuality is not disordered. Calling it disordered is a judgement.

You’re clearly under no obligation to share or confirm, but perhaps you suffer from some sort of mental handicap that leads to these consistently absurd and ridiculous exchanges every. single. time you post here?

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