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A discussion on homosexuality.

Started by Tank, June 29, 2011, 12:29:23 PM

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Tank

A person's sexuality is their own business. What adults do with other informed and consenting adults is their business. Some sexual practices involve greater health risks than others. This is not a thread about any of the above.

This thread is here to discuss the roots of homosexual behaviour, not take a moral or ethical standpoint on the behaviour.

The roots of an individual's behaviour are generally considered to be a balance between 'nature' (genetic and/or prenatal disposition) and 'nurture' (learned/cultural disposition). So an individual's sexuality could be hard coded and/or learned and anywhere between those two extremes of 100% nature to 100% nurture. Given the complexity of the human genome I would consider it practically impossible that a person with homosexual preferences could not come about through natural variations/mutations. I am also reasonably sure that social and cultural influences can be so strong that a persons sexual preferences could be influenced by there surroundings, upbringing and peer pressure during their sexually formative years.  

Please note I will report any and all derogatory comments made towards any sexual orientation. This thread is in the Science forum and it will be a polite discussion.
If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

OldGit

It's often said that evolution ought to breed out homosexuality if it's entirely inherited.  Even if it's only partly heritable, evolution ought to reduce it in the population.  Maybe it does, how would we know?

Tank

Quote from: OldGit on June 29, 2011, 02:59:33 PM
It's often said that evolution ought to breed out homosexuality if it's entirely inherited.  Even if it's only partly heritable, evolution ought to reduce it in the population.  Maybe it does, how would we know?

On the basis of simplistic natural selection (NS) the existence of homosexuality is counter-intuitive, either generated through nature or nurture. Yet all homosexual creatures (there are over 200 examples of species other than humans exhibiting homosexual behaviour) are the offspring of parents that, at least temporarily, exhibited heterosexual behaviour. So there must be a natural mechanism(s) that leads to homosexual behaviour. The fact that non-humans can exhibit homosexual behaviour also raises the question of how cultural/social drives, that do not exist in animals, can cause homosexual behaviour in animals. The inference it that cultural/social drives are not necessary for homosexual behaviours to occur, which indicates a genetic root in the behaviours.

List of animals displaying homosexual behaviour
Homosexual behavior in animals
Homosexual behaviour widespread in animals according to new study
Homosexual behaviour in animals: an evolutionary perspective

If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

Tank

A few years ago I recall watching a documentary on the Etoro tribe who live in Papua New Guinea. This tribes supernatural world view dictates their behaviour.

QuoteThe Etoro, or Edolo, are a tribe and ethnic group of Papua New Guinea. Their territory comprises the southern slopes of Mt. Sisa, along the southern edge of the central mountain range of New Guinea, near the Papuan Plateau. They are well known among anthropologists because of ritual homosexual acts practised between young boys and men of the tribe. The Etoro believe that young boys must ingest the semen of their elders to achieve adult male status and to properly mature and grow strong.

To me this illustrates perfectly how cultural imperatives, based on belief systems and institutionalised superstitions, can lead to behaviours that would be considered abhorrent in other cultures. Although in this case it is debatable whether the terms heterosexual and homosexual could/should be applied to this tribe as they have a unique world view and superstition.
If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

Will

Women in the maternal line of gay males have above average fertility. No such correlation exists with lesbians, however, so I don't know that we can explain them from an evolutionary standpoint, yet. It's just a matter of time, though.
I want bad people to look forward to and celebrate the day I die, because if they don't, I'm not living up to my potential.

Whitney

Quote from: OldGit on June 29, 2011, 02:59:33 PM
It's often said that evolution ought to breed out homosexuality if it's entirely inherited.  Even if it's only partly heritable, evolution ought to reduce it in the population.

Very few people fall at opposite sides of the spectrum...ie, very few people are totally gay or totally straight.  So any genetic factor for homosexuality could be passed along by those who fall somewhere in the middle.  Like if we found out there are two genes that make someone totally gay but just either one of those two being present made someone bi; it would be more frequent that people would be bi than fully gay and it would easily get passed along through the breeding bi population.

Not to mention that in social/herd species, such as humans, genes which benefit the group but do not necessarily benefit the individual get passed along.  For example, while a gay person may not reproduce they still would care about helping out family members who did reproduce.  So by helping out they increase the survival of their siblings offspring; and their genes indirectly get passed on since they are shared (perhaps recessive) in the siblings and their offspring.  I suck at explaining this stuff...I think this is explained in the Selfish Gene.

Anyway, much of what I have read tends to point to the hormone bath in the womb as being the most likely reason for variations in sexuality from the accepted norm; but it wouldn't' surprise me if there is a whole other set of genetic combinations that could be a cause too separate from hormone exposure int he womb.

Honestly, I think if our society were not so against homosexuality that more people would be open to considering themselves bi.  My reason for thinking this is roman culture...they encouraged homosexuality among men to preserve the virginity of their females so it was the norm (as long as they didn't practice it for life, eventually they were expected to take their female mate).  But our society considers homosexuality unmanly so young men are discouraged from exploring it.  Yet our society considers female homosexuality attractive so they are encouraged...and they do (girls gone wild etc).

DeterminedJuliet

I don't think that homosexuality is 100% genetic. No, I don't think it's a "lifestyle choice" or "unnatural" or any of that B.S. I believe that having a sexual identity is very real, but I would argue that any kind of sexuality, on any scale, is partly a social construct.

Our modern definition of homosexuality is pretty recent, actually. Several hundred years ago, there was no real concept of homosexuality as an actual orientation - yes, there were men who enjoyed sex with other men and women who enjoyed sex with other women, but it wasn't perceived of as an identity the way it is now. It was more of an action that people could perform or a slightly unorthodox "preference".

I think the most recent proponents of queer theory have actually backed off a little on arguing for biological pre-determinism in how we conceptualize sexuality. I think it's a good thing, but I'm a big fan of a sociological perspective on a lot of things, so maybe I'm a little biased :)

"We've thought of life by analogy with a journey, with pilgrimage which had a serious purpose at the end, and the THING was to get to that end; success, or whatever it is, or maybe heaven after you're dead. But, we missed the point the whole way along; It was a musical thing and you were supposed to sing, or dance, while the music was being played.

xSilverPhinx

Here are two links I posted on Phatmass (the Catholic website)

Is there a homosexuality gene? http://www.physorg.com/news84720662.html
Could homosexual genes be naturally selected? http://www.psychologytoday.com/blog/the-human-beast/200906/could-homosexual-genes-be-naturally-selected

I think it's more difficult to distinguish what is culture/nurture and what is nature/genetic, even though no one "gay gene" has been found (the simplifying is just awful).
I am what survives if it's slain - Zack Hemsey


Crow

As homosexuality isn't a unique feature to the human species but the animal kingdom and is well documented (another example article in addition to those Tank posted 1,500 animal species practice homosexuality) homosexuality may be a natural component of life.

From an evolutionary perspective at one point life branched out from hermaphrodite species that contain both sexual organs such as gastropods, slugs, earthworms, and certain species of fish that had no sexual preference. This could mean that as life evolved into species with distinct genders there may have been an element of the "survival of the fittest" at play, the species that preferred to procreate with both sexes or the opposite sex had a better chance of survival than those that did not. There is the a question of when did sexual preference come into play, I am guessing this came into effect with the evolution of sexual attraction, there may have also been the case that none selective, forced, and tribal reproduction may also have played a role.

There is also the social benefits of homosexuality such as creating stronger bonds between people in the same community as seen in Ancient Greece or Ancient Japan so it may have been viewed as a social benefit regardless of reproduction.
Retired member.

Tank

Quote from: DeterminedJuliet on June 29, 2011, 11:11:12 PM
I don't think that homosexuality is 100% genetic. No, I don't think it's a "lifestyle choice" or "unnatural" or any of that B.S. I believe that having a sexual identity is very real, but I would argue that any kind of sexuality, on any scale, is partly a social construct.

Our modern definition of homosexuality is pretty recent, actually. Several hundred years ago, there was no real concept of homosexuality as an actual orientation - yes, there were men who enjoyed sex with other men and women who enjoyed sex with other women, but it wasn't perceived of as an identity the way it is now. It was more of an action that people could perform or a slightly unorthodox "preference".

I think the most recent proponents of queer theory have actually backed off a little on arguing for biological pre-determinism in how we conceptualize sexuality. I think it's a good thing, but I'm a big fan of a sociological perspective on a lot of things, so maybe I'm a little biased :)
I think that for some individuals their homosexuality is 100% genetic. I also think that for some individuals their homosexuality is 100% choice. The proportion of people that exist in these two categories is debatable. But given the genetic evidence in animals and the social evidence in the Etoro these two categories do appear to exist. Thus in any individual the balance of these two factors leads to a spread of behaviours across a spectrum of heterosexual/bi-sexual/homosexual.

Thus sexual orientation is determined at the level of the personal/individual. Classification of an individual into a group is a singularly human activity driven by our evolved pattern seeking/matching brain.
If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

Asmodean

I think it can have both genetic and environmental causes - possibly even toxicological... Or a combination thereof.

Not all gay people are equally gay and there are many different stories and fates and circumstances out there. From personal experience, I have a friend who told me he knew he was gay from prepubescent age - even before he knew what sexuality, love or being gay for that matter was all about. And then there was another guy I knew... He started experimenting with boys as a part of being a responsibly stereotypical emo-kid... He stuck with it, but he doesn't really know what the hell he is in terms of sexuality even now.

Don't know too many lesbians, unfortunately... ( :P )
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DeterminedJuliet

#11
Quote from: Tank on June 30, 2011, 07:43:33 AM
Quote from: DeterminedJuliet on June 29, 2011, 11:11:12 PM
I don't think that homosexuality is 100% genetic. No, I don't think it's a "lifestyle choice" or "unnatural" or any of that B.S. I believe that having a sexual identity is very real, but I would argue that any kind of sexuality, on any scale, is partly a social construct.

Our modern definition of homosexuality is pretty recent, actually. Several hundred years ago, there was no real concept of homosexuality as an actual orientation - yes, there were men who enjoyed sex with other men and women who enjoyed sex with other women, but it wasn't perceived of as an identity the way it is now. It was more of an action that people could perform or a slightly unorthodox "preference".

I think the most recent proponents of queer theory have actually backed off a little on arguing for biological pre-determinism in how we conceptualize sexuality. I think it's a good thing, but I'm a big fan of a sociological perspective on a lot of things, so maybe I'm a little biased :)
I think that for some individuals their homosexuality is 100% genetic. I also think that for some individuals their homosexuality is 100% choice. The proportion of people that exist in these two categories is debatable. But given the genetic evidence in animals and the social evidence in the Etoro these two categories do appear to exist. Thus in any individual the balance of these two factors leads to a spread of behaviours across a spectrum of heterosexual/bi-sexual/homosexual.

Thus sexual orientation is determined at the level of the personal/individual. Classification of an individual into a group is a singularly human activity driven by our evolved pattern seeking/matching brain.

Yeah, I think I mostly agree, I just find it hard to think that a social label could ever really be applicable 100%. I mean, how do you measure "gayness"? Even if someone identifies as completely gay, does that mean they're "really gay"? Is that all being gay is? Identifying that way? What if someone has all of the genetic components, but doesn't identify that way; say a "reformed gay" who is a member of a religious group and he or she never commits a homosexual act in their life? Are they gay or not? What if I don't have the genetic components, but am drawn to something about the homosexual community and I decide I "want to be gay"? Am I gay if I'm accepted by other gay people? If I'm happy that way, who says I'm not "really gay"?

If someone is born on an island and never meets another human being in their life, can they be gay if they have some of the genetic components that might give them a tendency towards it? I would argue that they can't, personally. I'd argue that they couldn't be heterosexual, either. I think a sexuality NEEDS a certain amount of socialization to exist as a orientation that we would recognize. I agree that the genetics might either exist or not, but I would disagree that the genetics necessarily dictate the social manifestation in a person. I really think there are just too many variables.

I mean, I do agree that there are different "shades" of sexual orientation and genetic influence. I think I just don't like the idea that, if the genes were right, someone would be 100% pre-determined to be 100% homosexual. I just don't think people work that way.

Edit: I should also add that I think the only reason it's so easy for people to identify as "100% heterosexual" is because we live in an extremely hetero-normative culture. From birth, most of us are told that we are definitely, totally, completely straight and there are no other options. Heterosexuality is the default and you fall into that category unless you try to differentiate yourself. I think that's, largely, just as much a social construct as anything else I've argued here.
"We've thought of life by analogy with a journey, with pilgrimage which had a serious purpose at the end, and the THING was to get to that end; success, or whatever it is, or maybe heaven after you're dead. But, we missed the point the whole way along; It was a musical thing and you were supposed to sing, or dance, while the music was being played.

Twentythree

I am listening to an evolutionary biology class by professor Stephen C Stearns available on open culture. http://www.openculture.com/ He discussed environmentally activated adaptive change, also known as reaction norms. A lot of this goes into statistical analysis, which I'm not too clear on but the overall idea is that individual genes don't produce specific phenotypic expressions but rather genotypes can evolve a plasticity into phenotypic expression that is molded by environmental and developmental influences. To reduce this to its most basic form nature and nature are not mutually exclusive. In many aspects of evolutionary biology phenotypic expression is based on environment and development, not a hardwired expression of the genes. Professor Stearns uses the Cerebral cortex as an example as follows:

"If you were to look into the plasticity of my cerebral cortex, you would discover that it is incredibly plastic. In that when I am a little baby and I'm just born I have billions more connections in my nerve cells then I do when I'm seven years old.  A great deal of my mental development between birth and the age of seven has essentially been the remodeling of my cortex by plastic interactions with the environment."

Another interesting excerpt.

"Can we think of macro evolution as having constructed a vase within which the reaction norms sit, and the answer is no. The answer is no because some of the genes that are controlling the shape and the position of the eye spots (referencing butterfly wings) are also involved in determining the slopes and the shapes of the reaction norms. These two things are genetically entangled. And their entanglement is a case of the same gene having two different functions at different times in development. And natural selection will operate on it throughout the life-cycle. So it is not as though there are some things that are constraints that are not being changed and there are other things that are sort of tweaking the constraints a little bit. In fact the same genes are involved in producing both things."

So again this brings up the fact that selection happens at various stages of development, and thus phenotypic expression is a result of both genes and reactions to environment. So just off the top of my head I can imagine that humans have evolved the necessary chemistry in which long lasing pair bonds are forged, but many of our preferences and the things that stimulate those chemicals could be influenced by our development and our environment. This would lead to a tremendous plasticity to our tastes in sexual partners. The phenotypic expression of what we find attractive in a mate could be entangled with what culture tells us is beautiful and or acceptable, our natural drive to reproduce, and the chemistry that forms bonds in our brains.

Tank

#13
The discussion seems to be leading to a continuum that can be crudely depicted thus :-



While there are 4 crude categories it should be noted this matrix is really a juxtaposition of two continuously variable values.



If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

kelltrill

Very interested thread. Following it avidly, even though others have already expressed my opinions so I see no need to repeat them.
"Faith is generally nothing more than the permission religious people give to one another to believe things strongly without evidence."