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Genetics and sexuality.

TheOriginalHappyGoat

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Oct 4, 2010
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Margaritaville
I'm bringing this to the top, because if people do want to discuss it, it doesn't need to overwhelm an already lengthy thread about something entirely different below. This is a short primer on the complex relationship of genes to sexuality.

A few preliminary notes:

1. As Kinsey first demonstrated, sexuality isn't as simple as gay-straight-bisexual. Some people are sexually attracted to both sexes, but strongly prefer one over the other. Others are attracted to their own sex only in certain circumstances (e.g., the large number of men who have sex with men in prison, but only have sex with women outside of prison). Others are attracted only to pre-pubescent children. Still others are attracted to no one.

2. Sexual orientation and sexual behavior are not the same thing. Both can be considered traits, and potentially inheritable. But, being a behavioral trait, there is a stronger element of choice - for the lack of a better word - in sexual activity than there is in sexual orientation. Both may be partially affected by genes, environment and circumstance, but not necessarily in the same ratios.

3. "Genes" are not identical to "determined." Just because something is not genetic doesn't mean that it is a choice. Some of sexuality may be determined by genes, and some by environment, but even the environmental factors may not be a choice. Chemicals in the amniotic fluid, parenting choices, etc., are examples of non-genetic factors that may still diminish the "choice" an individual has.

Now, the first and primary way to study genetics is in two types of studies known collectively as "twin studies." Both can provide evidence of a genetic factor in behavior. The first way is by comparing identical to fraternal twins, and then comparing both to genetically-unrelated siblings (i.e., adopted). A trait that is at least partially genetic should show up the most among identical twins, who share the same genome. It should show up less often among fraternal twins, who share the same environment, but only 50% of their genes. And it should show up even less among adoptive siblings, who share no more genes between them that two random humans, but do still share (to an extent depending on their age when adopted, and difference in age between each other) some environment. When it comes to sexuality, lo and behold, that is exactly what we have found.

I cannot express how big of a deal those studies are. They pretty much seal the deal on their own. They are almost irrefutable proof that sexuality is at least partially genetic. All that is needed to turn an almost slam dunk into an epic Victor Oladipo highlight is to add other confirming studies, as well as some genetic studies to try to find potential genes at play. Well, studies have confirmed that there is a genetic role. The second type of twin study is to compare twins who were separated at birth with twins who have not been, and also with non-twins. Those types of studies have confirmed the genetic link to sexuality, along with a whole host of other traits, some of which are fairly disturbing, like religiosity, or a tendency to enjoy Salem cigarettes.

The next step is to do genetic studies. Well, scientists have identified at least 5 SNPs, or single-nucleotide polymorphisms - essentially points where a mutation has changed exactly one nucleotide base in the genetic code - associated with homosexuality.

This is what you might call home-run science. If sexuality is genetically-determined (at least to an extent), science predicts certain results in studies. And those studies confirm those exact results.

There is one more step in any study of inheritable traits, and that is to explain it. At first glance, one might think that homosexuality would be an evolutionary failure. Surely, it doesn't increase the fitness of an organism, since it dramatically reduces the likelihood said organism reproduces. I can think of at least three common explanations, listed here from least interesting to most interesting.

1. "Bad" luck. Perhaps the types of mutations that lead to homosexuality are just, for various chemical reasons, very common mutations. Some mutations are like this. The mutation that codes for sickle-cell disease, for example, probably arose spontaneously in at least five different human communities. It, of course, is a positive trait in malaria-heavy regions, so its survival was virtually guaranteed once it appeared.

2. Benefits outweigh the reduction in sexual activity likely to result in procreation. This is especially likely if bisexuality and homosexuality are related to the same genetic mutations. If bisexuality offers a survival advantage, bisexual individuals will be very likely to pass down the genes that, in at least some of their descendants, will express as homosexuality instead of bisexuality. This also works with the idea that sexuality is a scale, rather than a binary state.

3. Kin selection. This is by far the most viable and elegant solution. Kin selection is based on the idea that an individual's close relatives share many genes with that individual. If some of those shared genes lead to behavior that increases the likelihood of those close relatives surviving, then they can contribute to the passing down of genes, even if the individual does not reproduce directly. I'll give you a simple example. My sister shares 50% of my genes. If some of those genes result in behavior on my part that directly helps my sister survive and thrive to the point she is able to have at least one child, then I have helped ensure that at least 25% of my genetic code, up to closer to 50%, depending on how many children she has, will be "passed down" through my nieces and nephews.

For homosexuality, the theory of kin selection is applied in what is cleverly called "The Gay Uncle Theory." The theory states that a gay male will spend less (or no) energy raising his own offspring, and instead will help raise his sister's offspring. This increases the chance that the sister's children will survive, and each child is likely to share 25% of the gay uncle's genetic code. In other words, they have a 25% chance of carrying the gay gene themselves. This especially works with the idea that sexuality is only partially genetically determined, and also is affected by multiple genes, because it increases the likelihood that someone may carry some of the gay genes, but still themselves be straight, thus making it easier for those genes to be passed down.

So, here's what we have. We have studies which show a direct correlation between genetic relationships and sexuality. We have studies that pinpoint specific genetic mutations associated with those correlations. And we have a solid evolutionary explanation for why said mutations and behaviors may be positively selected for. In short, we have enough evidence to say that it is almost certain - as certain as science can be - that genes play at least some role in sexuality.

goat
 
I'm gonna take your deposition here

First, I'll stipulate that you are an expert in the subject matter of your post.

Q. Can you give us an objective definition of "homosexuality" that will allow the courts to evenhandedly apply laws naming homosexuals as a protected class?

Q. I agree with what I think is the point of your first paragraph. Do the studies show a correlation with such sexual uncertainty and different kinds of family situations during upbringing?

Q. Is it fair to describe sexual behavior with the same sex as a sexual preference?

Q. Regarding the twin studies. It appears that among male identical twins, if one is a homosexual there is approximately a 1 in 2 chance that the other will be homosexual also. Do environmental influences account for the differences?

Q. If environmental influences account for the difference, are there any identifiable environmental influences that will tend towards one orientation or the other?

Q. Can one's sexual orientation change during their lifetimes?

Q. If it does change, would brain plasticity play a role in that change?

Q. If environmental influences influence sexual orientation, can you say with a reasonable degree of probability that sexual orientation can't ever be changed with brain plasticity exercises?

That's all. I take don't take long depositions.










This post was edited on 4/15 11:00 PM by CO. Hoosier
 
Fun. I'll play.

Q. Can you give us an objective definition of "homosexuality" that will allow the courts to evenhandedly apply laws naming homosexuals as a protected class?

Homosexuality can be consider both a primary attraction to members of the same sex and the act of engaging in sexuality activity with members of the same sex. As a lawyer, I will point out that a protected class need not be a specific group of people, but merely a characteristic or method of categorization. For example, race, religion and ethnicity are protected classes; black, Christian and German-American are not. Homosexuals would not be a protected class. Rather, "sexual orientation" generally would be.

Q. I agree with what I think is the point of your first paragraph. Do the studies show a correlation with such sexual uncertainty and different kinds of family situations during upbringing?

The strong correlation between sexuality of fraternal twins would likely suggest that environment plays a role. What you might call "family situations" would likely be part of that environment.

Q. Is it fair to describe sexual behavior with the same sex as a sexual preference?

I would not describe behavior of any kind as a "preference," no. However, behavior is likely to correlate strongly with sexual orientation. This is why I explicitly distinguished between orientation and behavior during direct examination.

Q. Regarding the twin studies. It appears that among male identical twins, if one is a homosexual there is approximately a 1 in 2 chance that the other will be homosexual also. Do environmental influences account for the differences?

There are probably multiple other factors, but various environmental influences are likely to be one of major ones, perhaps the major one.

Q. If environmental influences account for the difference, are there any identifiable environmental influences that will tend towards one orientation or the other?

Yes. For example, first sons are far less likely to be homosexual than subsequent sons. We still don't understand why that is. Is it chemical - something in the amniotic sac? Is it because of natural tendencies of parents when it comes to raising second and third sons? Is it something else? We don't know for sure.

Q. Can one's sexual orientation change during their lifetimes?

We don't know. Sexual behavior can certainly change. See again the example of prisoners. Whether this represent a change in orientation, or simply a change in how a static orientation expresses itself based on changing circumstances is unknown.

Q. If it does change, would brain plasticity play a role in that change?

That's certainly plausible, but I would stress that the brain also changes in response to behaviors. It's not a one-way street.

Q. If environmental influences influence sexual orientation, can you say with a reasonable degree of probability that sexual orientation can't ever be changed with brain plasticity exercises?

We don't know enough about the nature of sexual orientation to suggest that there are any "exercises" that might purposefully change it. It's very likely that programs which purport this simply change behavior, not orientation. There are some studies that suggest "conversion therapy" can be successful, but it's also well-recognized that they are inconsistent and suffer from methodological problems. This is still an open question. Since I am a hostile witness, I will dramatically add at the end of my deposition that just because someone can change doesn't mean we have the right to expect them to.

This post was edited on 4/15 11:59 PM by TheOriginalHappyGoat
 
Gay, gay, gay, that's all anyone ever talks about here anymore! nm

nm
 
Sex, sex,sex, that's all anyone ever talks about anywhere anymore!

Some psychiatrists and scientists and sociologists oughta do some studies.
 
Sigh

can be
strong - but not certain - correlations
likely suggest
likely be
likely to
probably
likely
perhaps
less likely
still don't understand
don't know
unknown
plausible
don't know enough
likely
open question

You make a compelling argument.
 
Re: Sigh

He's a lawyer, what do you expect.

My wife shares her work related emails with me sometimes, that are abstract discussions among lawyers on the most brain numbing minutia you could ever dream up. If I dealt with it every day, I'd gargle drano. I work with numbers and finance, which others probably feel as negatively about, so each his own. This is at least an actual interesting topic.

I'm more amazed these goat has the hours in the day to write these diatribes.
Posted from Rivals Mobile
 
Exactly . . . . .

what is it about gays that attracts so much attention? In most of the contexts where sexualty is discussed, many people, and especially conservatives, just don't care about it; yet sexual identity is imposed by those who want sexuality to always be in the limelight. The same goes for skin color.

RFRA laws are not intended to be about marriage. In fact, most RFRA litigation is not about that, yet that issue was 100% of the discussion about IRFRA. This caused the IRFRA issues to be misstated and for some people deliberately misunderstood.












This post was edited on 4/16 12:03 PM by CO. Hoosier
 
A couple of observations/comments

First. An interesting question, that I have discussed before in various contexts, is: If we had the means to meaningfully influence an individual's sexual identity, should we apply that means? FWIW, one part of me is totally live and let live and who cares if there are ANY homosexuals. On the other hand, there would be zero homosexuals and without heterosexual relationships. Humans live in a strong social structure and traditional families have proven to be an excellent foundation to a well functioning, stable, and mutually advantageous society.

Second. Believing that sexual identity is "genetic" and thus unchangeable, therefore the social approach to the issue is over, is pretty easy. Once I became interested in brain plasticity, the whole role of genetics in who we are is an open question for me. At one level all behavior is genetic. That said, the pleasure/pain centers of the brain are very powerful and experiences, some of which we are not even aware, leave powerful imprints that influence everything we do. We know gonadal hormones change and that affects their influence on our synapses. I have a very good friend who changed her sexual orientation twice. I know some would pass that off by saying her orientation was really a preference. If that is true, then there might be no meaningful difference between orientation and preference despite the political baggage attached to those words.

Finally thanks for playing. The discussion is fascinating, but I really didn't learn much from your testimony.














This post was edited on 4/16 12:09 PM by CO. Hoosier
 
The results of the study are in...

and the doctors have found that that people who complain about talking about sex are old. :>)

Cue CoH's bigot post.

This post was edited on 4/16 12:05 PM by hoosboot
 
Yeah...conservatives totally don't care about sexuality/sexual orientation

They hardly ever talk about it, let alone obsess about it.
 
If an obsession over RFRA

is all it takes to be a conservative, then George Stephanopoulos, Governor Malloy, and you are conservatives.
smile.r191677.gif
 
In an attempt to elevate your snark to a more serious point

I totally disagree with the banning of log cabin republicans from the Western Conservative Summit. If you interpret this as an "obsession" with sexual orientation you might have a point. On the other hand, overall I think the liberals are constantly on the lookout for situations and events where they can insert the issue. The whole pizza/gay issue with IRFRA was the result of a reporter not resting until she found a quote to fit her agenda. That is what I am talking about.

On the larger point as far as I am concerned, banning speakers and points of view from most public events is never productive. Bans stilt the discussion and prohibits a legitimate points of view from being considered in the public square.
 
Re: In an attempt to elevate your snark to a more serious point

The problem goes back to Bush / Rove in 2004, which they made gay marriage a central campaign topic. Then you had conservatives in states all around the nation pushing constitutional amendments. The status today may be that conservatives don't care about sexuality, but that's an evolved position, the result of losing the culture war that social conservatives and the GOP rode so hard the prior decade.

You can't rewrite that history now.
Posted from Rivals Mobile
 
I didn't mention RFRA

I thought we were talking about sexuality and sexual orientation. Those are the things that conservatives TOTALLY are disinterested in discussing.
 
Oh...I think liberals are obsessed with sexuality & sexual orientation, too

Did I say otherwise elsewhere? I merely took exception to the idea that conservatives are just disinterested bystanders in the discussion and I think you and 20 both offered obvious examples of why that was a mistaken contention.
 
I rarely have a desire to post here or actually read here

due to the volume of typing it would require to express to some what is needed if the particular backgrounds were not present and the available time that in my haste only serves to confuse others with what I said. However, I do want to offer here (and perhaps the info exists somewhere or a few questions I would have) that confounded within the results may very well be any nurturing effects. What you really need is those studies where the twins are separated from each other…and that could lead to effects of home life etc. Still, if the twins lived together….I'm not sure what conclusions should be drawn and not sure it matters for most...
 
There wasn't much to learn.

The only point of this thread was demonstrating how we know that sexuality is affected by genetics. If you already knew that, I wasn't going to teach you much.
 
Two things

First, you must have missed it, but I did mention twins separated at birth.

Second, regular twin studies show a difference between identical and fraternal twins. That difference can ONLY be genetic.
 
I went to the links again

and just don't have time to read the third or long one. I read the first...scanned quickly the others and my comments are still there. it appears that the nature versus nurture argument is still there. Nature is confounded in all I read. They take a genetic data and see if they are homosexual and compare the genetics of identical and fraternal and so forth. what we don't see or I missed if I did was any genetics of "straight men? to see if straight men have the certain genes as well. Still, what I want to see is "identical twins" that were raised in different environments, not just households and see that data.

It was not clear whether there was any data on identical twins separated and studied...that would help remove a nature effect...
 
"Twins separated at birth"

Was the theme and in the title of the second article! If you don't have time to read AND you refuse to take my post at face value, fine. But maybe hold off the commentary until you do have time to read. This entire sub thread could have been avoided if you just read first.

This post was edited on 4/18 11:03 PM by TheOriginalHappyGoat
 
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