Is that really in need of an explanation, though? Some people are repulsed (by stuff), and others aren’t.
It seems to me that any mental feature that can be explained should be explained. It makes great sense to me why there are people who feel visceral disgust at the prospect of sexual activity with their siblings, and that there are men who feel visceral disgust at the prospect of sexual activity with men. (Interestingly enough, this sort of ‘homophobia’ seems more heritable than homosexuality is, which makes sense—this is actually selectively positive!) So what’s going on with a man who feels visceral disgust at the prospect of sexual activity with women? Is it the same sort of homophobia reflex, but miswired? Is it something else?
If you don’t find explaining things interesting, well, I recommend a career in something other than science :P
Not every individual in a species has to be geared for reproduction
How does evolution work? There are two core pieces: variation, and selection. Variation is the uninteresting bit, and selection is the interesting bit: entities that reproduce themselves become more common in later generations, because they reproduced themselves.
It’s not a question of what “has” to happen. It’s a question of “what happens.” Similarly, explanations need to fit together with every other part of what we see. Suppose a model where gay uncles help people in their family raise children, are generous with their wealth to family members, and so on. In such a case, does it make sense for families to disown gay sons?
(Remember, we’re trying to explain why 3% of men are gay. We can’t accept any explanations that would make, say, half of men gay, because that doesn’t fit with the facts!)
It makes great sense to me why there are people who feel visceral disgust at the prospect of sexual activity with their siblings, and that there are men who feel visceral disgust at the prospect of sexual activity with men.
The first is clear to me, but the second isn’t. Why would homosexual male sex be a bad thing, as long as it didn’t cause men not to seek out women as well?
Of course some resources would be spent on it instead of on mating, but humans have a lot more sex in general than necessary for procreation, and many other ‘unnecessary’ social activities like games. The usual reasons given (e.g. bonding) also make sense between male pairs. Such sex could (counterfactually) also relieve some sexual tension without inviting jealousy, since another man might provide variety and quick simulation but not replace the long-term woman partner.
This seems to apply even more strongly to women, whose fitness doesn’t benefit from promiscuous heterosexual sex like male fitness does.
We can’t accept any explanations that would make, say, half of men gay, because that doesn’t fit with the facts!
We also need to understand why those explanations are in fact wrong, otherwise we’re risking retrofitting explanations to the data by choosing explanations without fully understanding what makes them right.
Why would homosexual male sex be a bad thing, as long as it didn’t cause men not to seek out women as well?
Primarily, that; secondarily, disease risk. It seems to me that there are many men who put up with women only for the sex, and if they could get that satisfaction elsewhere, they would.
The usual reasons given (e.g. bonding) also make sense between male pairs.
It looks like a number of ancient societies had sanctioned male-male sexual relationships, often but not always of the ‘old mentor / young protege’ variety. But it’s hard for us to tell how common those were (specifically, how many of those partnerships were actually sexual, instead of just knowing that some were).
This seems to apply even more strongly to women, whose fitness doesn’t benefit from promiscuous heterosexual sex like male fitness does.
Interestingly, female bisexuality seem much more common than male bisexuality, and also considerably more fluid.
That’s an excellent point I missed. If promiscuity with other men came at the expense of promiscuity with other women, it wouldn’t be a problem. But male promiscuity is often limited only by the number of willing and attractive partners, so it would still increase the number of overall partners.
It seems to me that any mental feature that can be explained should be explained.
The explanation is the same as most other “repulsions”, that you happened to develop a response of visceral disgust to a particular stimulus. Most people are repulsed by something; vegetarians can be repulsed by the concept of eating meat, men can be repulsed by reading excerpts from Twilight, and children can be repulsed by green vegetables. None of these need “explanations”, beyond the obvious: because humans are malleable and can learn to hate things, particularly if they are taught to hate it. If people can learn to be repulsed by meat, or green vegetables, or squishy chick-lit, they can damn well learn to be repulsed by women. So I say that repulsion towards women doesn’t need an explanation, since people develop (and overcome) visceral responses to all sorts of things all the time. I’ve seen nothing to show me that revulsion to women is somehow inherent to homosexuality, and while I’m not asking you to prove it, I hope you have a good reason for believing it.
Suppose a model where gay uncles help people in their family raise children, are generous with their wealth to family members, and so on. In such a case, does it make sense for families to disown gay sons?
Do they? Or is that just another assumption of yours? Do you have a good reason for believing this one?
The explanation is the same as most other “repulsions”, that you happened to develop a response of visceral disgust to a particular stimulus.
“Happened” is typically used when a result is undetermined or not strongly expected: “the die happened to come up a six.” It would sound weird to use it when a result is determined in advance: “the cup happened to fall once I let it go.”
I’ve seen nothing to show me that revulsion to women is somehow inherent to homosexuality, while I’m not asking you to prove it, I hope you have a good reason for believing it.
It’s certainly not inherent to all homosexuality. Whenever this topic comes up, this part of American on Purpose comes to mind:
I also remember feeling physically ill at the sensation of the bristle on his chin against mine and I’m still haunted and creeped out by that. My gay male friends tell me that they have felt the same about experimental physical encounters with women.
(I don’t seem to have this reaction, myself. But my experiences are also minimal.)
Do they?
Does who what? Do families disown gay sons? Yes; my first boyfriend was kicked out by his family, and it seems a disproportionately large fraction of homeless youth are LGBT, with some large fraction of those claiming their parents forced them out.
“Happened” is typically used when a result is undetermined or not strongly expected: “the die happened to come up a six.” It would sound weird to use it when a result is determined in advance: “the cup happened to fall once I let it go.”
Not “undetermined”, but the result of a process complex enough that it’s very difficult to predict the outcome or identify the root cause.
Does who what? Do families disown gay sons? Yes; my first boyfriend was kicked out by his family, and it seems a disproportionately large fraction of homeless youth are LGBT, with some large fraction of those claiming their parents forced them out.
I should be more clear: “Does it make sense for families to disown gay sons assuming that homosexuality improves group fitness” is a loaded question because it carries with it an assumption that disowning gay sons has evolutionary roots, or is ingrained behavior in humans, or is common. And I’m not convinced of any of these things. After all, my family didn’t disown me, and it seems like disowning gay sons is becoming increasingly uncommon.
You asked whether it made sense for families to disown gay sons. Does it make sense for families to disown children for being the wrong religion? Does it make sense for families to disown children for being pregnant?
the result of a process complex enough that it’s very difficult to predict the outcome or identify the root cause.
Difficult’s a two-place word, and so I’m not sure it makes much sense to argue about whether or not something is ‘objectively’ difficult, instead of difficult at various states of knowledge.
it carries with it an assumption that disowning gay sons has evolutionary roots, or is ingrained behavior in humans, or is common.
It’s not quite that disowning gay sons has evolutionary roots, but that disowning gay sons is not so heavily disfavored as to be extincted. For example, cultures where childbirth is prohibited mostly die out, and so on. But even less obvious things that have an effect on reproductive success are strongly motivating; in cultures with prohibitions against masturbation, those prohibitions are mostly not followed; in cultures where doctors tell mothers to avoid touching their infants because of disease risk, those prohibitions are mostly not followed, and so on. (The impulse for mothers to touch their babies seems very strong, and also very healthy—it actually lowers disease risk by informing the mother what antibodies she needs to produce for her child, and seems critical for proper psychological development.)
And traditional behavior gives us an imperfect window into the economics of the past, which is what’s under discussion when we talk about historical selective fitness. If gay sons were helpful enough with nephews and nieces that it was as if they had had their own children, it seems to me they would be welcomed and lauded as examples of loving selflessness. But if gay sons were reproductively disadvantageous, and in particular if it was reasonable to expect that homosexuality is contagious, then there’s little cost and some reproductive benefit to forcing them out of the home.
(I should note that the hypothesis that one gene causes both female fecundity and male homosexuality is also consistent with disowning gay sons, but I think that one has other challenges.)
After all, my family didn’t disown me, and it seems like disowning gay sons is becoming increasingly uncommon.
Thankfully, people are much more motivated today by individual and relationship satisfaction, neither of which disowning is helpful with. (My family didn’t disown me either.)
Does it make sense for families to disown children for being the wrong religion?
It suspect it made sense for religions to disown members that fail to disown their children for being the wrong religion.
Does it make sense for families to disown children for being pregnant?
It looks like control over sexuality was a big deal, and as a first-order effect it seems that signals of that control would heavily impact someone’s price on the sexual marketplace. As a second-order effect, it seems that the harsher penalties are for not being controlled, the more likely people are to submit to control. But in less status-stratified societies? Probably not—and it seems like this is mostly a class thing in the societies that I’m familiar with.
This is mostly my speculation, though—I haven’t read much on evolutionary accounts of how parents should respond to teenage pregnancy in various environments. I expect someone has thought about this problem.
And traditional behavior gives us an imperfect window into the economics of the past, which is what’s under discussion when we talk about historical selective fitness.
Traditional behavior is so widely varied, though, that it’s difficult to draw any conclusions. Some traditional societies practiced polyandry, others, polygamy, and still others, levirate marriage, and avunculism, and so forth. Some traditional societies were accepting of homosexuality and even transgenderism. You say that cultures that prohibit childbirth die out, but many diverse cultures have a thriving tradition of monasticism (which is even worse for reproductive fitness than homosexuality!)
If gay sons were helpful enough with nephews and nieces that it was as if they had had their own children, it seems to me they would be welcomed and lauded as examples of loving selflessness.
Would they? “Gay” is a recent category; traditional societies did not attempt to classify humans in that way and it only became popular when religious authorities attempted to criminalize it and early psychologists attempted to medicalize it. Men were not “gay” or “homosexual”, they were more or less inclined towards other men.
And traditional behavior gives us an imperfect window into the economics of the past, which is what’s under discussion when we talk about historical selective fitness.
I think we should keep in mind just how far back we’re talking. I’m not saying we inherited homosexuality from our common ancestor with the modern fruit fly, but at least our common ancestor with other great apes. Framing the question as why would it be selected for in the context of human societies is probably wrong, when what we want to know is why it wasn’t sufficiently selected against given it already existed (I doubt we’ll ever figure what advantage it gave the proto-ape whose social structures we’ll never know). Once a trait already manifests in 3% of the population, it takes work to get rid of it, and even within that 3%, it was doubtful the case that 0% of them reproduced while 100% of heterosexual men reproduced. I’m sure it wasn’t exactly parity, but it’s possible there is no explanation in terms of the organization of human societies except for we’re really optimized to enjoy sex, sometimes that wire gets flipped, and it doesn’t provide an advantage, but it also doesn’t give enough of a disadvantage to completely disappear within 300,000 years.
Don’t forget also, that if some gene combo is necessary but not sufficient, and requires other developmental factors to manifest that don’t manifest in your brothers and cousins (which seems to be the case if it’s only 20% between twins), then when they reproduce, even if you don’t, the gene still gets passed on. Take me, for example. I’m not gay, but I am sterile and don’t want kids anyway. Nonetheless, I have 3 sisters and 13 cousins that have had kids so far. Without doing the exact math, off the top of my head I’m guessing at least 80-90% of whatever I’m carrying made it to the next generation.
Edit: Also, one last thing is we don’t know the prevalence in the ancestral population. Given it’s roughly 100% bisexual in such a closely related other species, it could have been fairly high in the common ancestor, obviously not 100% obligate, but more than 3%, and it actually has been selected against, a lot, just not enough to get us to zero yet.
It seems to me that any mental feature that can be explained should be explained. It makes great sense to me why there are people who feel visceral disgust at the prospect of sexual activity with their siblings, and that there are men who feel visceral disgust at the prospect of sexual activity with men. (Interestingly enough, this sort of ‘homophobia’ seems more heritable than homosexuality is, which makes sense—this is actually selectively positive!) So what’s going on with a man who feels visceral disgust at the prospect of sexual activity with women? Is it the same sort of homophobia reflex, but miswired? Is it something else?
If you don’t find explaining things interesting, well, I recommend a career in something other than science :P
How does evolution work? There are two core pieces: variation, and selection. Variation is the uninteresting bit, and selection is the interesting bit: entities that reproduce themselves become more common in later generations, because they reproduced themselves.
It’s not a question of what “has” to happen. It’s a question of “what happens.” Similarly, explanations need to fit together with every other part of what we see. Suppose a model where gay uncles help people in their family raise children, are generous with their wealth to family members, and so on. In such a case, does it make sense for families to disown gay sons?
(Remember, we’re trying to explain why 3% of men are gay. We can’t accept any explanations that would make, say, half of men gay, because that doesn’t fit with the facts!)
The first is clear to me, but the second isn’t. Why would homosexual male sex be a bad thing, as long as it didn’t cause men not to seek out women as well?
Of course some resources would be spent on it instead of on mating, but humans have a lot more sex in general than necessary for procreation, and many other ‘unnecessary’ social activities like games. The usual reasons given (e.g. bonding) also make sense between male pairs. Such sex could (counterfactually) also relieve some sexual tension without inviting jealousy, since another man might provide variety and quick simulation but not replace the long-term woman partner.
This seems to apply even more strongly to women, whose fitness doesn’t benefit from promiscuous heterosexual sex like male fitness does.
We also need to understand why those explanations are in fact wrong, otherwise we’re risking retrofitting explanations to the data by choosing explanations without fully understanding what makes them right.
Primarily, that; secondarily, disease risk. It seems to me that there are many men who put up with women only for the sex, and if they could get that satisfaction elsewhere, they would.
It looks like a number of ancient societies had sanctioned male-male sexual relationships, often but not always of the ‘old mentor / young protege’ variety. But it’s hard for us to tell how common those were (specifically, how many of those partnerships were actually sexual, instead of just knowing that some were).
Interestingly, female bisexuality seem much more common than male bisexuality, and also considerably more fluid.
That’s an excellent point I missed. If promiscuity with other men came at the expense of promiscuity with other women, it wouldn’t be a problem. But male promiscuity is often limited only by the number of willing and attractive partners, so it would still increase the number of overall partners.
The explanation is the same as most other “repulsions”, that you happened to develop a response of visceral disgust to a particular stimulus. Most people are repulsed by something; vegetarians can be repulsed by the concept of eating meat, men can be repulsed by reading excerpts from Twilight, and children can be repulsed by green vegetables. None of these need “explanations”, beyond the obvious: because humans are malleable and can learn to hate things, particularly if they are taught to hate it. If people can learn to be repulsed by meat, or green vegetables, or squishy chick-lit, they can damn well learn to be repulsed by women. So I say that repulsion towards women doesn’t need an explanation, since people develop (and overcome) visceral responses to all sorts of things all the time. I’ve seen nothing to show me that revulsion to women is somehow inherent to homosexuality, and while I’m not asking you to prove it, I hope you have a good reason for believing it.
Do they? Or is that just another assumption of yours? Do you have a good reason for believing this one?
“Happened” is typically used when a result is undetermined or not strongly expected: “the die happened to come up a six.” It would sound weird to use it when a result is determined in advance: “the cup happened to fall once I let it go.”
It’s certainly not inherent to all homosexuality. Whenever this topic comes up, this part of American on Purpose comes to mind:
(I don’t seem to have this reaction, myself. But my experiences are also minimal.)
Does who what? Do families disown gay sons? Yes; my first boyfriend was kicked out by his family, and it seems a disproportionately large fraction of homeless youth are LGBT, with some large fraction of those claiming their parents forced them out.
Not “undetermined”, but the result of a process complex enough that it’s very difficult to predict the outcome or identify the root cause.
I should be more clear: “Does it make sense for families to disown gay sons assuming that homosexuality improves group fitness” is a loaded question because it carries with it an assumption that disowning gay sons has evolutionary roots, or is ingrained behavior in humans, or is common. And I’m not convinced of any of these things. After all, my family didn’t disown me, and it seems like disowning gay sons is becoming increasingly uncommon.
You asked whether it made sense for families to disown gay sons. Does it make sense for families to disown children for being the wrong religion? Does it make sense for families to disown children for being pregnant?
Difficult’s a two-place word, and so I’m not sure it makes much sense to argue about whether or not something is ‘objectively’ difficult, instead of difficult at various states of knowledge.
It’s not quite that disowning gay sons has evolutionary roots, but that disowning gay sons is not so heavily disfavored as to be extincted. For example, cultures where childbirth is prohibited mostly die out, and so on. But even less obvious things that have an effect on reproductive success are strongly motivating; in cultures with prohibitions against masturbation, those prohibitions are mostly not followed; in cultures where doctors tell mothers to avoid touching their infants because of disease risk, those prohibitions are mostly not followed, and so on. (The impulse for mothers to touch their babies seems very strong, and also very healthy—it actually lowers disease risk by informing the mother what antibodies she needs to produce for her child, and seems critical for proper psychological development.)
And traditional behavior gives us an imperfect window into the economics of the past, which is what’s under discussion when we talk about historical selective fitness. If gay sons were helpful enough with nephews and nieces that it was as if they had had their own children, it seems to me they would be welcomed and lauded as examples of loving selflessness. But if gay sons were reproductively disadvantageous, and in particular if it was reasonable to expect that homosexuality is contagious, then there’s little cost and some reproductive benefit to forcing them out of the home.
(I should note that the hypothesis that one gene causes both female fecundity and male homosexuality is also consistent with disowning gay sons, but I think that one has other challenges.)
Thankfully, people are much more motivated today by individual and relationship satisfaction, neither of which disowning is helpful with. (My family didn’t disown me either.)
It suspect it made sense for religions to disown members that fail to disown their children for being the wrong religion.
It looks like control over sexuality was a big deal, and as a first-order effect it seems that signals of that control would heavily impact someone’s price on the sexual marketplace. As a second-order effect, it seems that the harsher penalties are for not being controlled, the more likely people are to submit to control. But in less status-stratified societies? Probably not—and it seems like this is mostly a class thing in the societies that I’m familiar with.
This is mostly my speculation, though—I haven’t read much on evolutionary accounts of how parents should respond to teenage pregnancy in various environments. I expect someone has thought about this problem.
Traditional behavior is so widely varied, though, that it’s difficult to draw any conclusions. Some traditional societies practiced polyandry, others, polygamy, and still others, levirate marriage, and avunculism, and so forth. Some traditional societies were accepting of homosexuality and even transgenderism. You say that cultures that prohibit childbirth die out, but many diverse cultures have a thriving tradition of monasticism (which is even worse for reproductive fitness than homosexuality!)
Would they? “Gay” is a recent category; traditional societies did not attempt to classify humans in that way and it only became popular when religious authorities attempted to criminalize it and early psychologists attempted to medicalize it. Men were not “gay” or “homosexual”, they were more or less inclined towards other men.
I think we should keep in mind just how far back we’re talking. I’m not saying we inherited homosexuality from our common ancestor with the modern fruit fly, but at least our common ancestor with other great apes. Framing the question as why would it be selected for in the context of human societies is probably wrong, when what we want to know is why it wasn’t sufficiently selected against given it already existed (I doubt we’ll ever figure what advantage it gave the proto-ape whose social structures we’ll never know). Once a trait already manifests in 3% of the population, it takes work to get rid of it, and even within that 3%, it was doubtful the case that 0% of them reproduced while 100% of heterosexual men reproduced. I’m sure it wasn’t exactly parity, but it’s possible there is no explanation in terms of the organization of human societies except for we’re really optimized to enjoy sex, sometimes that wire gets flipped, and it doesn’t provide an advantage, but it also doesn’t give enough of a disadvantage to completely disappear within 300,000 years.
Don’t forget also, that if some gene combo is necessary but not sufficient, and requires other developmental factors to manifest that don’t manifest in your brothers and cousins (which seems to be the case if it’s only 20% between twins), then when they reproduce, even if you don’t, the gene still gets passed on. Take me, for example. I’m not gay, but I am sterile and don’t want kids anyway. Nonetheless, I have 3 sisters and 13 cousins that have had kids so far. Without doing the exact math, off the top of my head I’m guessing at least 80-90% of whatever I’m carrying made it to the next generation.
Edit: Also, one last thing is we don’t know the prevalence in the ancestral population. Given it’s roughly 100% bisexual in such a closely related other species, it could have been fairly high in the common ancestor, obviously not 100% obligate, but more than 3%, and it actually has been selected against, a lot, just not enough to get us to zero yet.