"I'm hesitant to reply because I don't want to come off as an annoying poly evangelist. I think people should be whatever they want, and nobody should have to poly unless they're enthusiastic about it. But responding to the post in the spirit in which it was intended:
I didn't intend for the "you can have more than one friend" argument to invalidate anyone's jealousy. I see it brought up to counter a certain annoying tendency where people are like "but how can you possibly love two people at the same time, that's not what love is, you're insulting one of them by not making them your sole priority!" People seem really committed to this deep philosophical principle that they just made up, and that they would abandon instantly if it conflicted with anything socially acceptable, eg having two children who you both love equally. I agree that once you have abandoned this fake principle, you can still feel normal jealousy.
I agree that some ingredients for jealousy are genetic, but like every genetic thing they're heavily modulated by culture. In ancient Greece, men wouldn't let their wives out of the house because it would be considered some kind of insane provocation; in Saudi Arabia, men won't let other men see their wives' faces; in modern America, most men don't really mind their wives going out partying with their male coworkers. In medieval Arabia it was considered normal for women to share their husbands with other wives; in Renaissance France it was considered normal for women to let their husbands have mistresses; in parts of the deep South it would be scandalous to learn your husband was looking at another woman. In polygynous cultures most people get along fine being polygynous; in polyandrous cultures most people get along fine being polyandrous; in those tribes where everyone sleeps with each other and raises children together, most people get along just fine with that. In evangelical subcultures everyone agrees that porn is "cheating" and women get really jealous and betrayed if they learn their husband looked at porn; in more liberal subcultures, everyone agrees porn doesn't matter and women don't care. If you scratch the surface, you can find jealousy-shaped things in the most poly relationships - there are a lot of men who eg might be fine with their wife going on dates with other people, but would be really jealous if they heard she'd fallen in love with them. I think the same malleability of the genetic jealousy impulse which allows Saudi Arabia and liberal America to both be stable equilibria allows polyamory to be a stable equilibrium too. That doesn't mean everyone will like it, anymore than everyone likes Saudi or liberal American norms, but I don't think it violates human nature.
When a poly person says something like "I think if you were more open-minded you'd find you were able to tolerate poly just fine" (which I agree is annoying if unsolicited), I think a good analogy would be an American saying this to a Saudi. They're not claiming the Saudi wouldn't feel immediate repulsion at the thought of a bunch of other men staring at his wife's face, get upset, and want to go back to Saudi Arabia. They're saying that if they managed to really assimilate into a culture where that kind of thing is normal, it will feel normal, at least for most people (I think there are some American men who are sad that people can constantly stare at their wives, and American norms are a genuine sacrifice for them, but I think this is less common than a Saudi person would expect. Americans shouldn't claim that their cultural expectations eliminate Saudi-level jealousy, just that they make it much less common.)
Another way to look at this might be: jealousy is a natural human urge (pretend I included all the appropriate caveats here). Wanting to have sex with lots of people is also a natural human urge (ibid). Different relationship styles balance these urges in different ways, and no style is going to be able to allow both of them for everybody, so you use your culture to set expectations, and as long as those expectations are clear most people usually do pretty well, except a small minority who will hopefully be able to go off and start a subculture which is friendlier toward their own needs."
I use the "jealousy and friendship" analogy simply to explain polyamory to monogamists who can't fathom the mindset. I never assume it's going to cause someone to reorient their own relationship style since I suspect much of that is hardwired. I recently met some distant relatives on my mom's side (through Ancestry) and discovered that many of them are polyamorous like me. What could explain this correlation? Whatever genes are responsible for jealousy may be less expressive in our family line so traits like compersion end up becoming dominant. I do think the reality is some complex interplay of genes and environment determining relationship orientation and not that different from sexual orientation.
The fact that many people who identify as monogamous still highly value sexual novelty but also have high jealousy quotients are then often either 1) cheaters or 2) serial monogamists indicates there is a spectrum rather than a binary on this.
On sexual selectivity: At first glance, it may seem that low jealousy levels would be evolutionarily disadvantageous, but that's only the stick side of things. The carrot of valuing sexual novelty means that greater opportunities for more sexually successful types (such as alpha males) means their genes get passed on to a greater degree while less sexually successful types lose out. If a social structure evolves that supports that (such as polygamous societies), then the carrot doesn't ever get slowed down by the stick.
Scott Alexander's reply:
"I'm hesitant to reply because I don't want to come off as an annoying poly evangelist. I think people should be whatever they want, and nobody should have to poly unless they're enthusiastic about it. But responding to the post in the spirit in which it was intended:
I didn't intend for the "you can have more than one friend" argument to invalidate anyone's jealousy. I see it brought up to counter a certain annoying tendency where people are like "but how can you possibly love two people at the same time, that's not what love is, you're insulting one of them by not making them your sole priority!" People seem really committed to this deep philosophical principle that they just made up, and that they would abandon instantly if it conflicted with anything socially acceptable, eg having two children who you both love equally. I agree that once you have abandoned this fake principle, you can still feel normal jealousy.
I agree that some ingredients for jealousy are genetic, but like every genetic thing they're heavily modulated by culture. In ancient Greece, men wouldn't let their wives out of the house because it would be considered some kind of insane provocation; in Saudi Arabia, men won't let other men see their wives' faces; in modern America, most men don't really mind their wives going out partying with their male coworkers. In medieval Arabia it was considered normal for women to share their husbands with other wives; in Renaissance France it was considered normal for women to let their husbands have mistresses; in parts of the deep South it would be scandalous to learn your husband was looking at another woman. In polygynous cultures most people get along fine being polygynous; in polyandrous cultures most people get along fine being polyandrous; in those tribes where everyone sleeps with each other and raises children together, most people get along just fine with that. In evangelical subcultures everyone agrees that porn is "cheating" and women get really jealous and betrayed if they learn their husband looked at porn; in more liberal subcultures, everyone agrees porn doesn't matter and women don't care. If you scratch the surface, you can find jealousy-shaped things in the most poly relationships - there are a lot of men who eg might be fine with their wife going on dates with other people, but would be really jealous if they heard she'd fallen in love with them. I think the same malleability of the genetic jealousy impulse which allows Saudi Arabia and liberal America to both be stable equilibria allows polyamory to be a stable equilibrium too. That doesn't mean everyone will like it, anymore than everyone likes Saudi or liberal American norms, but I don't think it violates human nature.
When a poly person says something like "I think if you were more open-minded you'd find you were able to tolerate poly just fine" (which I agree is annoying if unsolicited), I think a good analogy would be an American saying this to a Saudi. They're not claiming the Saudi wouldn't feel immediate repulsion at the thought of a bunch of other men staring at his wife's face, get upset, and want to go back to Saudi Arabia. They're saying that if they managed to really assimilate into a culture where that kind of thing is normal, it will feel normal, at least for most people (I think there are some American men who are sad that people can constantly stare at their wives, and American norms are a genuine sacrifice for them, but I think this is less common than a Saudi person would expect. Americans shouldn't claim that their cultural expectations eliminate Saudi-level jealousy, just that they make it much less common.)
Another way to look at this might be: jealousy is a natural human urge (pretend I included all the appropriate caveats here). Wanting to have sex with lots of people is also a natural human urge (ibid). Different relationship styles balance these urges in different ways, and no style is going to be able to allow both of them for everybody, so you use your culture to set expectations, and as long as those expectations are clear most people usually do pretty well, except a small minority who will hopefully be able to go off and start a subculture which is friendlier toward their own needs."
I use the "jealousy and friendship" analogy simply to explain polyamory to monogamists who can't fathom the mindset. I never assume it's going to cause someone to reorient their own relationship style since I suspect much of that is hardwired. I recently met some distant relatives on my mom's side (through Ancestry) and discovered that many of them are polyamorous like me. What could explain this correlation? Whatever genes are responsible for jealousy may be less expressive in our family line so traits like compersion end up becoming dominant. I do think the reality is some complex interplay of genes and environment determining relationship orientation and not that different from sexual orientation.
The fact that many people who identify as monogamous still highly value sexual novelty but also have high jealousy quotients are then often either 1) cheaters or 2) serial monogamists indicates there is a spectrum rather than a binary on this.
On sexual selectivity: At first glance, it may seem that low jealousy levels would be evolutionarily disadvantageous, but that's only the stick side of things. The carrot of valuing sexual novelty means that greater opportunities for more sexually successful types (such as alpha males) means their genes get passed on to a greater degree while less sexually successful types lose out. If a social structure evolves that supports that (such as polygamous societies), then the carrot doesn't ever get slowed down by the stick.