The Karolinska Institute in Sweden continues to make news with genetic and sex research. Now they come forward with a study in the Proceedings of National Academy of Sciences which finds a link between relationship stability and a gene variant. Here is the KI news release:
Link between gene variant and relationship difficulties
[PRESS RELEASE, 2 September 2008] Scientists at Karolinska Institutet have found a link between a specific gene and the way men bond to their partners. The results, which are presented in the scientific journal PNAS, can lead to a better understanding of such problems as autism and social phobia.
“There are, of course, many reasons why a person might have relationship problems, but this is the first time that a specific gene variant has been associated with how men bond to their partners,” says Hasse Walum, postgraduate student at the Department of Medical Epidemiology and Biostatistics.
He stresses, however, that the effect of this genetic variation is relatively modest, and it cannot be used to predict with any real accuracy how someone will behave in a future relationship.
Hasse Walum and his colleagues made use of data from The Twin and Offspring Study in Sweden , which includes over 550 twins and their partners or spouses. The gene under study codes for one of the receptors for vasopressin, a hormone found in the brains of most mammals. The team found that men who carry one or two copies of a variant of this gene allele 334 often behave differently in relationships than men who lack this gene variant.
The incidence of allele 334 was statistically linked to how strong a bond a man felt he had with his partner. Men who had two copies of allele 334 were also twice as likely to have had a marital or relational crisis in the past year than those who lacked the gene variant. There was also a correlation between the mens gene variant and what their respective partners thought about their relationship.
“Women married to men who carry one or two copies of allele 334 were, on average, less satisfied with their relationship than women married to men who didnt carry this allele”, says Hasse Walum.
The same gene has been previously studied in voles, where it has been linked to monogamous behaviour in males.
“The fact that the corresponding gene has proved important for similar behaviour in voles makes our findings even more interesting, and suggests that the thoroughly studied brain mechanisms that we know give rise to strong bonds between individual voles can also be relevant to humans”, Hasse Walum concludes.
The team hopes that greater knowledge of the effect of vasopressin on human relations will one day give science a better understanding of the causes of diseases characterised by problems with social interaction, such as autism.
Publication:
Hasse Walum, Lars Westberg, Susanne Henningsson, Jenae M. Neiderhiser, David Reiss, Wilmar Igl, Jody M. Ganiban, Erica L. Spotts, Nancy L. Pedersen, Elias Eriksson and Paul Lichtenstein
Genetic variation in the vasopressin receptor 1a gene (AVPR1A) associates with pair-bonding behavior in humans, PNAS Early Edition, 2-5 September 2008.
Ah, the mysteries of human behavior. I think there is probably something to this. Men who look to bonding problems with their parents for the reason they do not feel connected to their mates might better look elsewhere. None of this is destiny but it makes some sense that the mechanisms underlying bonding are variable in their application due to DNA. Furthermore, none of this suggests that monogamy is not valuable or attainable — it just means some must work harder at it.
Drowssap,
About the “how would the trait have survived until now” debate. A few more ideas. Maybe it was hidden in a portion of the population, like in this diagram. One possible explanation for that: it was an evolutionary hammer-and-anvil that would have kept men either fighting to pass their genes on or to fail. Evolution, in this view, was never a leisure game. It would explain why the trait became socially visible during times when society afforded more physical comfort. It goes together with less physical activity, less conflict, less aggressiveness, and so on.
I’d really want to see the full brain mechanism behind the sex-aggression-stress interconnection identified. My prediction is that the sexual response was never a precise instinct in humans, like in other mammals, because New World primates have lost the olfaction-based gender discrimination organ and have increasingly relied on visual cues in order to identify food and mates. The reptilian reproductive brain system was already built on top of aggression, because it’s the basic animal dimension that ensures goal-directedness in fighting and preying. Reproduction was, in its rudimentary form, male-female dominance, which was built on the same rewarding paths as aggression and feeding.
The most interesting question would be now if New World monkeys increasingly relied on the visual system how did they manage to identify gender status in order to reproduce? Well, they didn’t have any special organ for that anymore like mice, they relied on the most basic male-female animal difference, which was aggression. They defaulted on aggression and combined visual identification with the old and waning olfactory system. This adaptation would have had enormous advantages for something very basic, like more foraging and hunting possibilies identified from the distance, far superior to the possibilities afforded only by the smelling sense. This means that humans no longer have a special error-free system in the brain to ensure that genders are emotionally identified either as 1 or 0, either as female (green light for reproduction) or male (green light for territorial aggression). It’s mostly the interplay between sight and aggression. Aggression probably regulates humans’ internal gender state, which influences how genders are emotionally identified, their “gender” status. (Note: I’m not talking about psychologists’ concept of aggression, I’m using the term in the animal research sense.) It explains why humans are not attracted to any individual of the opposite sex (like mice), but only according to preference inside a gender category, which is something more elaborate, more developmental, more depending on sight. So the rest would be the effect of imprinting and social gender segregation. This would also explain primates’ variety in sexual behaviour.
Evan
I heard Stephen Hawking talk about that on the radio today. Physics is way over my head but the collider experiment has got me excited… assuming we don’t get sucked into a blackhole. 😎
Drowssap,
They better speed up research, because next month the planet is getting sucked in by a black hole from under the Franco-Swiss border. It’s gonna make everything spaghetti. 🙂
Evan
Well you are right. There probably are gay men who have sex with more women than the average straight guy in an attempt to overcome their SSA. But I doubt a broad average of gay men would find that to be typical.
WIthin a year or so a scientist somewhere is going to announce that he found the sex attraction switch in animals. One chemical will probably create attraction to females, another attraction to males. At that point this whole debate is going to change forever. That’s my humble, nearterm prediction. 😎
Or he could sleep with as many possible women to prove himself that he is more attracted to them. The power of the environment cannot be underestimated. But you’re right, if you mean men who under no circumstances are able to be attracted to any female. I don’t think this type is very common. Maybe adults who used to have any form of GID during childhood or the most obvious “sissies.” But then, if scientists are right about the fact that the “gay brain” is more efeminised and less masculinised, gay men should be as attracted to women as straight women could be. Something doesn’t add up in this story.
Evan
If somebody doesn’t like chess odds are good that they don’t play it much.
If a guy finds men attractive chances are he doesn’t sleep with too many women.
I would guess that gay men have less children during virtually every era, but particularly the modern and prehistoric. I don’t see the Hulk Hogan of the ancient world sharing his harem, and the modern environment doesn’t compel gay men to have families.
I guess we have to wait for official numbers, but that’s gotta be a safe bet.
The trait may not actually be exclusive in the population, like 5% of 100% SSA-ed and 95% of 100% OSA-ed. The trait could be uniformly distributed. It wouldn’t matter that some 5% don’t have kids if the rest who have some degree of SSAs have kids. Most of them probably have kids. Bailey keeps saying that SSA-ed men have less kids, but you can only know that if they report it. One of the chapters in his book is called ‘Gay, Straight or Lying.’ Lying is evolutionarily adaptive, gay is not. But Bailey likes controversy. He knows that however the cards will fall, it’s going to produce some soul-searching and purging.
Evan
Selection against intelligence didn’t get into full swing until the 20th century. It’s a byproduct of modern birth control.
We can’t know for sure until we build a time machine. 😎
But before villages and organized society the world was competitive and dangerous. Survival of the fittest reigned supreme. If only a few men had kids in each tribe why predict that any significant number would be from gay men? I would predict the exact opposite. Agrarian societies popped up about 5000 years ago and I can see how gay men would have families in those societies. Society forced them. But as soon as large, anonymous urban environments showed up gay fertility plumetted towards zero again. Only advanced technology could change that.
Some might say it comes easier for “less cleverest” individuals to have kids. Even today, smarter people have fewer kids and deliberate more before having any. I think we cannot really estimate how selection operated many thousands of years ago. Human populations dynamics are very messy, there are ups and downs, there are baby boomers and bottlenecks created by plagues or sudden shortage of resources. It’s never a progressing line which selects the best. Different types of selection and drift operate at the same time with varying strengths according to the size of the population. What is more, cultural practices worked in spite of evolution. Evolutionary theory assumes that the primal force behind fitness dynamics is competition. It’s a very limited point of view. People have been using many types of strategies in order to bond and reproduce, and competition is just one among many. There were tribes in which reproduction was never a personal decision or impulse. It was all ceremony sanctioned by the elders. Ancient tribal practices had completely different directions than nature-driven selection. Who knows? It might have even been the case in some tribes that the men who were more required to reproduce were actually the less aggressive for some purposes. I don’t completely buy evolutionary explanations. It’s a fashionable paradigm right now and it will pass. We’ll keep what is valuable from it.
Evan
My personal guess is that 15,000 years ago, during the Hunter Gatherer era gay men had virtually no children at all. I’ve read that on average only 20% of men had children back then. That’s the main reason that men are bigger than women. Every generation for about 250,000 years the biggest, strongest, most motivated, cleverest, etc. etc. men had nearly all of the children. The other 80% had few to none. On the flip side most women had children in every generation.
I doubt that gay men (if there were any) had many children before the Agrarian era where life was organized and society and rules began to develop.
Evan
Fragile X is genetic while Downs Syndrome is the result of healthy genes being scrambled as they assemble. The incidence rate for stuff like that is always super low.
Mental retardation (unless it’s from something like Fragile X), Schiz, Autism, mood disorders, etc. are all very common and are typically triggered by the environment. As an example 20% of Schiz cases are triggered by flu virus. Genes make people susceptible to this stuff, but they don’t typically cause it.
Drowssap,
There are many things to say on this subject.
Mental retardation is estimated to affect 1-3% of the population in various forms. Fragile X Syndrome is genetic and has an incidence of 0.03%. It affects males more than females. Down Syndrome has an incidence of about 1 to 800 live births per year. The male-to-female ratio is 1:3. Autism spectrum disorders have a prevalence of 6 cases per 1000 people, at a 4.3:1 male-to-female ratio. Estimated to be on the rise – or maybe better diagnosed.
Schizophrenia occurs at varying rates throughout the world, up to 1% in lifetime prevalence. Severe depression, two times more common among women, have very different rates in different countries, within a 3-16% interval. Heritability was estimated in a Swedish twin study at about 42% in women and 29% in men. The World Health Organisation predicted that by 2030 it will become the second burdensome disease. Obviously genetics do play a role, but the increasing incidence strongly points to environment.
Personality disorders have a prevalence from 9% to 15%.
Anxiety disorders have been found to have the highest prevalence among DSM-IV disorders, at about 18%.
Some of these conditions are exclusively genetic, others have low genetic contributions. But these are disorders. Bocklandt and Hamer did not refer to male homosexuality either as being a disorder or as resulting from a genetic disorder. Therefore, comparing the prevalence of disorders caused by some genetic component with the prevalence of homosexuality is not going to yield meaningful conclusions (not all disorders actually reduce fitness). Homosexuals are not unable to have children or to have sex with partners of the opposite sex. They report stronger attractions to the same sex and stronger preference for sexual behaviour with the same sex. People who reported identifying as gay, having had same-sex behaviour and primary same-sex attractions, were documented to be about 5.5% in an Australian twin study. People who reported primary same-sex attractions were about 14.5%, but 8.8% acted on them. 6.4% of people who reported not having SSAs engaged in same-sex acts. This happens in a certain environment in which the society model is heterosexual. It means that we can expect any degrees of same-sex attractions to be underreported, especially lower ones.
Another issue is that not all same-gender oriented people are or have been sex-atypical, so their cases cannot be explained by genetic feminisation or low masculinisation effects, which is what Bocklandt and Hamer attempted. Maybe there are more types of same-sex attractions, depending on the physical variability of sexual objects (attraction to strongly masculine types, attraction to moderately masculine types, attraction to juvenile types, etc – each one of them excluding the other types), with different pathways leading to this outcome. This is very important, because having a good explanation implies being able to predict orientation, by checking one or a few markers in any given individual. Right now this is impossible for sexual orientation: brain studies show distributions of sizes, connections and so on that overlap between homosexual and heterosexual groups. It looks like homosexuality is a category of its own, which cannot be thrown together with disorders. It’s a possibility of the human brain under certain conditions and variations of development and response to environment. That’s why studying it will make us understand a lot more about heterosexuality itself. It will be interesting to see what would make someone unable to have any degree of opposite-sex attractions, if this is true in a number of people.
Please see the above comment where I said that sexual arousal was probably built on the most basic animal dimension which dealt with external threat. The direction of the sexual response seems to go together with one’s response to stress and one’s aggressive dimension. If an individual is primarily same-sex attracted, whether or not was subjected to traumatic events, he is also more likely to experience greater vulnerability to stress. These things go together, because less aggressiveness, a less masculinised physical constitution and greater vulnerability to stress reduce a male’s capacity to attract females. But they don’t make someone unable to reproduce. We must not forget that we live in an age which emphasises the importance of physical pleasure in general and of attractions as a key component of sexuality and as a basis for stable relationships. In another society in which the individual was not as important as today, finding a partner was not left to chance or preference as much as today. Even today, actually, we don’t get into relationships with people we are most attracted to or who are most attracted to us. If that were true, then all the media built around movie stars or all the internet pornographic businesses would go bankrupt. All these things are related, they are outlets for fantasies. My point was that focusing too much on attractions as a basis for understanding the reproductive fitness of sexual behaviours may be misleading. They are important, but they are not everything at play. We don’t live in an environment with a few fluctuating variables, we live in a full-blown life. There are many types of pressures, one of them is the pressure to bond and many men may have chosen to do that against their primary attractions in order to live inside relationships that promissed to be more stable and life-supporting. That could have worked in spite of genes or, even more impressive, in spite of man’s natural tendency to seek physical pleasure. You wouldn’t see that in bonobos, the sex-crazed monkeys. Humans have an unusual capacity to work against their own nature for some purposes. It’s our mentality that makes us consider how they would have behaved in the past by today’s standards or expectations. Life was neither as comfortable nor as stressful as today in the past. That can explain many things about how our biologies are differently exercised compared to other periods in time. We have no idea what it meant 15,000 years ago, for instance.
Evan
From a hypothetical standpoint this is probably correct. If a gene goes haywire pretty much anything is possible. But do fundamentally important genes go haywire 3% of the time? Nope. This would occur in something like one out of hundreds or perhaps thousands of people. And of course then somebody would have to figure out why the gene went haywire in the first place which would probably come back to environment.
I also noticed that they didn’t compare this concept with other genes that go haywire 3% of the time and crater fertility or fitness. None exist.
I find it interesting that the Fraternal Birth order effect is viewed as positive while the gay germ theory is viewed as negative and they are both almost identical theories.
Fraternal Birth Order Effect
Testosterone triggers the mother’s immune system to attack the developing fetus’ brain and damage something. This creates homosexuality.
Gay Germ Theory
A germ, or the bodies immune response to a germ damages something in the brain of a developing fetus’ or child. This creates homosexuality.
Evan
One of the first lines is also one of the most telling.
Regarding hormones and SSA
Without doing $1 worth of research and armed with the most basic understanding of genetics and biology any highschool kid could have predicted that. No common level of hormones could ever produce homosexuality in 3% of men. It’s a biological impossibility. The fact that so many scientists jumped on a concept that could never in a million years be true is scary. They let a few tiny pieces of data that weren’t well understood obscure the reality that natural selection works.
…ok back to reading this thing. 😎
Evan
RIGHT ON! 😎
Thanks for the reading!!!
I think the hormone theory is fading although not yet dead.
Drowssap,
Let me give you something interesting to chew over. Hamer and his colleague Bocklandt don’t believe anymore in the hormones theory. Here’s the paper. They tackle some possible genetic mechanisms for SSAs. But, OFC, they are geneticists, therefore they’re biased by profession.
Ann
To be totally honest I’m not impressed with the focus on genetics research in general. As far as kids and young adults are concerned our genes are RARELY the cause of anything that reduces fertility, fitness or whatever. It’s pretty much environment in almost every case.
Pretend a scientist tells you that he just discovered a condition that reduced fertility in young people and it was very common. That’s all you need to know. If you guess, “it must be triggered by something in the environment” your chances of being correct are virtually 100%.
Drowssap,
Do you think the Human Genome Project yields any information for this? If not currently, could it?
Warren
If genes do correlate with SSA I will be interested to see if scientists know what they actually do.
If these genes turn out to be immue system related this one is all over.
Furthermore if somebody finds a seasonal birth pattern for SSA the time for wondering is over.
I’ve been wondering about this for about 5 years and whatever way it goes I’ll be happy to have an answer. 😎
RE: The comment on the genetic studies underway, I agree we will learn much from these studies and should wait for their results before going much further with statements regarding what role genes play.
Evan
I believe there probably are genes out there that both increase and decrease the odds someone will become homosexual. But what does that even mean? Scientists know that humans have genes that increase or decrease someone’s likelihood of catching HIV. But no part of HIV is contained in human DNA even if specific genes make us more or less susceptible to it. If something reduces fertility in young people it comes back to environment 99.9% of the time.
Evan
How could genetic drift spread negative traits over any significant period of time? If a gene is bad it wouldn’t be able to spread for very long if at all. Even in a group of 100% genetic disordered people, eventually a mutation would fix the disorder and the new gene would spread until it became fixed in the population. It might take 10,000 years but it would happen every single time. Either that or the group would go extinct.
Group selection is the whole basis for the gay gene theory and I don’t buy that one. SSA shows no pattern of inheritance and has a super low identical twin concordence rate. Not to mention the recent work out of Sweden says that homosexuality is about 2/3rds environment.
Could it be genes? Yes. But why even guess that it might be? Nothing has ever worked like the gay gene theory and so far the evidence falls squarely in the environmental column.
Evan,
we live in an information society and theories can sometimes influence people’s motivations
This I believe is one of the biggest factors in this entire discussion. I grew up in a time when society moved from a place of being personally responsible for ones actions to one of individual rights whereby we were being indocrinated into believing that everything that we are and do is built into our genes and therefore we are not responsible for our own actions. Where we are at today is that it is a combination of these, that our genes do dictate somewhat how we see the world but that the way we respond to these cues influences who we become.
Drowssap,
Right now this is just mental exercise. We need to see the results on those genetic studies from Northwestern and UCLA to understand more about this issue. They should appear any moment soon.
This must be discussed, though, because we live in an information society and theories can sometimes influence people’s motivations.
Drowssap,
Erm, actually natural selection can work at many levels — individual, kin, groups. There are many types of natural selection. One of them is balancing selection, which makes individuals who have two different alleles at the same genetic locus (heterozygotes) have greater fitness than individuals who have two similar alleles (homozygotes). This gives heterozygotes resistance to sickle cell anemia, for instance, but it also maintains the gene even if some phenotypes are affected. Even disruptive selection might have worked in the past, because people could have cooperated in order to reproduce.
Genetic drift can result in the selection of one bad trait that eventually becomes fixed and can threaten extinction of a group. But in larger groups, different types of natural selection and genetic drift work at the same time, exerting different types of pressures.
One of these mechanisms could maintain some genetic effects for a variety of sexual orientations, but that doesn’t mean that they were actually recognised as such in the past. Evolutionary explanations typically ignore cultural effects. That can be a big factor in some societies.
Evan
Natural selection, and mutation occurs on the individual level. Genetic drift can only occur with neutral traits, not negative traits. Once a gene becomes negative in a given environment it either
A) Disappears
B) Randomly (and luckily) mutates into a beneficial form and starts spreading all over again
Drowssap,
Natural selection works in large populations. In small populations, genetic drift can have rampant effects.
Drowssap wrote:
I think imprinting works differently at different ages. For instance, imprinting creates attachment to a caregiving adult which was present during the early years of development. Later on, this stage is consumed (just like suckling) and the child is ready for other, more complex developments. During middle childhood imprinting might work in a different way, the stronger impression this time being the adversive one, instead of the soothing one. A small baby is more insecure and more impressed by the source of security. A boy has already built a world map: for him what is calm and reassuring is boring and ordinary and what is a source of nervousness one day may become exciting and impressive, a source of arousal.
It has to do with the development of the stress system and, IMO, that structure has shared functions with what sustains aggression and sex in the male brain. I’ll give a few reasons in support of this idea:
— men and women differ in their response to stress: men have the fight-or-flight response, women the tend-and-befriend (fact);
— gay men are at a higher risk for psychiatric disorders specific to women (fact);
— gay men score less on the aggressiveness scale (fact);
— gay men show greater amygdala activation than straight men on preferred sexual imagery (fact);
— gay men show amygdala connectivity similar to that of women and have greater blood flow than straight men in the same brain area even in a resting state, without any relevant stimuli (fact).
My intuition tells me that this system can work one way or the other in different people of the same gender depending on how it’s developed and/or put to strain. If the stress response is outward — beat the stimuli or dodge it — then sexual arousal builds around a possessive drive in relation to the “smaller sex”, if the stress response is inward — take the blow and try to cushion it — then sexual arousal is inflated by passivity to stimuli in relation to the “bigger sex”. This system is probably simple, because it’s so old that it had very simple, not very precise, but fast reactions. And it makes sense, in a way, because sexual arousal was probably built around and ontop of the most basic animal dimension, which is the one that regulates response to external threat. This response is sexually dimorphic, that’s why female heterosexuality was built based on insecurity and need for protection and male heterosexuality was built on aggression and the possessive drive. Anything that disrupts those basic levels changes the whole game for that person.
The scientific news is that professional people in this field are already working in this direction. The “gay sheep” guy, Charles Rosselli, UCLA geneticist Sven Bocklandt and Eric Vilain have published this year a paper on the effects of prolactin expression in the sheep brain, looking for the way it’s involved in the development of the stress axis. They found something in the amygdala area, but it’s too early to say.
Returning to your question. Abuse and any traumatic events can affect the development of some of the brain areas involved in the stress response. It may not even be committed by a certain gender. Maybe simply depressing some brain areas can produce a reduction in assertive behaviours, later isolation from gender peers and then attractions. But the imprinting effect was related to taunting, not trauma. The boy who is taunted is targeted for being fearful. That creates a reinforcing effect on a predisposition and the boy associates his vulnerability with the action of a certain agent — typical boys. I’m not sure that the taunting is necessary for the development of male SSAs, maybe just the aforementioned atypical development of the stress system. On that background, any event could have imprinting effects, like a boy seeing pornographic material, or seeing someone naked or any chance event would strongly impress his mind. In this way, biological predispositions get triggered by random environmental events. A different boy having no such predispositions could simply ignore the stimuli. When SSA-ed adults are studied by their reports, they might remember some events, like being taunted, or seeing something, or even being abused, but others would quickly point to similar events which did not have a similar effect on other boys. That’s why sexual orientation seems an impossible subject to study. Many things which are probably relevant look like confounding variables. I’m sure we’re gonna return to some of them.
Evan
Most gay men were taunted by boys during their childhood but shouldn’t that push them towards attraction to women? Why would we suspect that abuse by other men commonly shuts down OSA and at the same time creates a strong attraction to men?
Shouldn’t men that were abused by men be more likely to associate with and be attracted to women?
Evan
But that’s just another version of the gay gene theory. A gene(s), combined with pretty normal social circumstances (or hormones or ?) produces a trait that makes men find women totally unattractive and other men super attractive. And for whatever reason 250,000 years of natural selection can’t do anything about it, even if they don’t have kids.
That makes no sense to me.
Drowssap,
Most studied gays have reported some degree of gender atypicality. Many of them have been taunted for that during childhood. This might be strong enough to act as an imprinting event. It’s a by-product of environmental conditions on a certain background of predispositions. But the main effect of imprinting remains that of early attachment and later bonding, which mostly promotes heterosexuality, given that most people are not sex-atypical. But even if genes would have a say in this process, it’s not necessary that today’s homosexuality would be the product of natural selection.
Nature can work in blind ways. In fact, evolution is blind, the most recent organisms are not the smartest or strongest. They are the product of different adaptations that worked in changing environments. Like if you live in a world of geeks, it doesn’t serve you much being an alpha male. Unless you get your own niche and serve some ecosystemic purpose you get outsmarted and eliminated by the little men. So fitness is something relative to what environment you live in. If the environment goes through an abrupt change, fitness gets a new direction and the maladapted get gradually eliminated. It’s not the best who survive, it’s the best fitted for a particular environment.
If someone who lived in the cave dwelling period was less aggressive than the others, he would have had very small chances to survive, because groups had less specialised niches than communities and they didn’t afford guys who couldn’t hunt or fight. But in a community, less aggressive guys could have found their own niche and even become recognised for some qualities associated with less aggressiveness. I still think that whatever traits are associated with less aggressiveness were by-products of people living in bigger communities (even rural ones). That makes people more pressed to cooperate for whatever purpose they have, including finding resources, pairing and reproducing. But they also become more stressed about having to keep track of so many faces, physical hierarchies, roles, power games and so on. The benefits must have been really great to keep people inside greater communities.
But then, some traits could simply be the result of genetic drift, so there would be no actual “purpose” or adaptation that lead to the appearance of that trait during a certain period of time. They would become obvious and problematic only in larger populations, when natural selection would come into play. That’s probably why homosexuality has become so visible today – because we live in larger communities.
Evan
For sure we don’t know. But what would make us think that nature would build a system like this for homosexuality? Straight vs. gay isn’t like generous vs. stingy. Natural imprinting doesn’t make sense unless it’s really, really forced over a long period of time. But most gay men grow up in normal, boring homes.
Drowssap wrote
Imprinting is just one mechanism which ensures that an individual will be attracted by at least one kind of person. It looks like a mechanism which promotes bonding and preserves certain traits in the gene pool. If the mother has some physical traits, then the son will be looking for those traits; same for the father and daughter. But I am quite sure this doesn’t work only with parents. I know a few people whose choice of partners reflected a different type of imprinting, which involved more relatives than parents.
But this is a mechanism which secures a particular preference inside a gender category. You could have more preferences, but this one would be included. Of course, no one knows what makes one prefer one gender right now. It’d be interesting to see this experiment done with gays, and see whether there is any evidence for the imprinting effect and if not why.
Stephen Kanitz
Genes mutate by accident. I believe all mutations are the result of transcription or other errors. Nearly all errors are bad, but those that aren’t spread like wildfire. If this one is at all common it offered benefits in some environments. My guess is that this gene is effective in environments most people wouldn’t find all that pleasing. Sounds like a gene that works well during times of chaos or instability.
No average parent consistently pushes their son towards homosexuality for a long period of time. SSA would have to be triggered by some sort of early life “flash” imprinting process.
But why would nature build a “flash” imprinting process for orientation? There would have to be individual adaptive benefits to both straightness and homosexuality just like there is for agressiveness vs. passiveness.
What is more interesting is that doubling a gene is not a mutation but a transcription error, which are much much more frequent, and happens all the time. So doubling 334 showed up frequently and when we moved to cities like Jericho 10.000 years ago, the effects were much more pronounced. Infidelity in small groups can easily be curbed by social pressure, not so in big cities.
So here we may have the reason for the rise of Religion and the many injunctions found in the bible, the ten commandments, the pro-family movement, etc. The creation of rules rather than social pressure. My guess many more genes will be found , especially on the X gene, that only women transmit to their sons. Males never pass on their X gene to sons, only their Y gene.
But doubling genes are like wildfire, they occur frequently and this one spreads very fast.
Drowssap,
TBH, I’m interested in heterosexuality more than in homosexuality. And imprinting is one way in which nature makes sure that we will be attracted to at least one type of person of the opposite sex. I’ve seen this myself in me and in other people. I am drawn to many types of women, but one type has some features which look like my mother when she was young. I can’t explain why I am attracted to other types of women, it must be that imprinting might work with more templates than one.
I think these researchers were modest in their experimental design. They should have extended the search to other relatives too, like brothers, sisters and cousins. I know one woman that is very attracted to one guy who, if you ask me, looks a lot like her brother, but nothing like her father. So, it looks like imprinting might depend on other factors, like what kind of connection might a daughter have had with her father. Maybe it’s about some impression that must be strong enough to imprint one’s imagination. Or it’s about a preferential connection between the parent and the child.
But we can also imagine a few interesting questions that might throw a light on why nature works this way. What happens if a daughter has a gay father – is she attracted to guys who look like her gay father? Is this a safety valve in nature which ensured less typical males could find mates even if they were less assertive? What kind of woman might have chosen to pair with an atypical guy and later have a daughter that would be attracted to atypical guys? Maybe she was imprinted in the same way. What about sons who grow up to be gay? Are they imprinted by their mother in any way? If the boy is sex-atypical, is he the object of attraction for more outgoing women? I can think of many questions which avoid later gender preference, because that’s a slippery subject and I don’t completely rely on adult reports.
Evan
I understand imprinting that might influence specific tastes. But in what way do families commonly imprint lifelong homosexuality onto kids? Society and 99.9% of parents do everything possible to imprint heterosexuality onto all kids and yet 3% end up gay.
Readers of the Exotic Becomes Erotic theory might remember that one of the mechanisms responsible for the development of attractions was imprinting. There’s new evidence for the effect of imprinting in human attractions.
Children use opposite sex parent as template for a partner. (the news)
Facialmetric similarities mediate mate choice: sexual imprinting on opposite-sex parents. (the study)
Warren – you might be interested in this subject, which brings new substance to what environmental factors could mean, in interactional terms. The same Hungarian researcher – Tamas Bereczkei – published a paper on the same subject four years ago, co-authored by Glenn Weisfeld. I can’t post the link, just look for this DOI: 10.1098/rspb.2003.2672.
Just one allele for a vasopressine receptor and they could establish a measurable effect on the quality of relationships. Another variant of the same allele on the 12q site was linked with autism. It gives a new perspective on what comorbidity could look like one day.
I loved this one and it makes sense.
In some environments less bonded males have the advantage. In other (probably more stable, modern environments) bonded males have the advantage.
Compare that with SSA. Assuming it’s not built into the system for some sort of group benefit how would it work?
There are no environments where SSA has the edge over OSA. Why would we expect to find a bell curve for male sexuality when only one game plan has worked since the beginning of time?