Should polyamory be forbidden?

The worst thing you can hear from your partner is that there’s someone else, but the second worst thing you can hear form your partner is “Do you want to open up our relationship?” This is a relatively innocuous question, because it suggests that they still love you, but it still suggests they love somebody else more. But should this even be a question somebody feels okay about asking, or should everyone be pressured, as much as possible, to avoid polyamory?

In theory, there is nothing wrong with it. If three people come together and decide to be in a relationship with each other, the costs and benefits of their decision are fully internalized, and their agreement is consensual and fully informed, so there is nothing wrong with it. We can expect these choices to be beneficial to the polyamorous while hurting nobody. In practice, allowing polyamory can cause some problems.

To begin, think about what the consequences of a prohibition on cheating are. Cheating is distinct from polyamory, but this will help us understand the situation better.¹ Allowing cheating has many consequences. Primarily, it allows a partner to shop around for alternatives before they or their partner decide to cease all sexual and romantic activity. Through this, either partner can gather more information before changing relationships more explicitly. Second, the other partner continues to invest in their partner when they otherwise wouldn’t. That means things like gifts, showing they care about their partner with their words, etc. If they knew their partner had become disinterested enough to cheat, they would have a lower estimate of the benefits of that kind of treatment. Finally, attention is likely directed away from their primary partner and toward someone else, immediately lowering the benefits of the relationship.

When cheating is prohibited, it’s harder for a partner to gather information about alternatives, whether through conversation or sex (since some people are simply not compatible in bed). The benefit from the prohibition is that the other partner won’t lose as much by investing in a relationship that is likely to end soon, unbeknownst to them. Rather than cheating, their partner will likely end the relationship outright. They’ll also receive more attention from their partner. Generally speaking, people prefer to prohibit cheating, so perhaps the information problem isn’t that bad, especially in comparison to the losses from redirected attention and misinvestment.

Archaically, prohibitions on cheating were also useful for men to make sure the child they’re taking care of isn’t someone else’s. But most people today are not partnered for this purpose, so the focus isn’t on them.

So what about polyamory? This doesn’t allow you to gather information in the way cheating does, because you have to ask first. Less attention is a part of the deal, so we can assume it doesn’t cause problems.

But there’s still an investment problem for monogamous people. If one partner thinks “Well, I can ask about opening up this relationship”, they’re going to be thinking that for some time before they actually ask. If they don’t think they can ever ask that, they’re going to think either “I should just end the relationship” or “Well, alright, this is good enough anyway”. The former case is the one you want to happen earlier if your partner secretly isn’t feeling good about things.

Oftentimes, somebody asking to open up a relationship actually does like the current relationship and just thinks it would be improved by another partner. They’ll often know their partner well enough to only ask if they think it’s likely to work out, too. But when it doesn’t work out, and that will happen, it will hurt like hell for the person on the receiving end. This is the most impactful problem caused by permissiveness toward polyamory: your permissiveness about this kind of behavior, combined with the permissiveness of others, can establish a social norm that soils good relationships. On the bright side, this can, in theory, also take a struggling relationship and save it.

There’s a clear difference between from-the-start polyamory and opening a relationship. Hypothetically, you could permit from-the-start polyamory or from-the-start openness while forbidding modifications to the mental contract you sign when beginning a monogamous relationship. But it seems that polyamory very often begins with an implicitly monogamous relationship being modified.

The other problem with permissiveness towards polyamory is that people might just be stupid and horny when they do this and it’s a recipe for disaster for the people involved. I’m skeptical about this one because I think people are generally smart. It’s worth noting that non-monogamous people are just as happy with their relationships as monogamous people, but this is an obvious case of survivorship bias. And as the author, Nicola Davis, notes, “The research has limitations, including that the type of non-monogamous relationship was not considered in many of the studies; participants were often recruited via social networks, meaning they were not necessarily representative of the whole population; and the studies relied on self-reporting, which can be biased.”

This is a rather famous visual description of survivorship bias from Wikipedia. Planes that return from battle are often hit in non-fatal places. If you armored these places, it wouldn’t help as much as armoring the things that really matter. Similarly, observed polyamorous relationships might be better than unobserved polyamorous relationships that ended as a consequence of the polyamory.

If we want to deal with survivorship bias, we should look at the duration of polyamorous relationships, rather than reported satisfaction. Data is scant, but we do have a survey performed by Aella that can tell us about this. If you focus on the primary partners polyamorous people have, these relationships do, indeed, not last as long. The differences are very small for younger people, but get wider with age. Go check out the article. There’s a lot of interesting results in there, like people over 35 being more likely to be polyamorous, rather than less. I suspect that one happened because people taking Aella surveys tend to be sexually weird, with the exception of young people who are simply more comfortable with thinking about things like polyamory or transgender identification.

Poly relationships not lasting as long doesn’t necessarily mean polyamorous people are being stupid. Relationships can end for multiple reasons, other than a lack of satisfaction. Because the same pattern was observed for people who do not identify with their birth gender, compared with people who do, Aella suspects the pattern emerged because older people have often exited relationships to begin their current one only once their cultural environment became more accepting.

Another potential confounder Aella found was that polyamorous people tend to have larger age gaps. Larger age gaps might kill relationships, since poly relationships that lost a long time “seem to involve more similarly-aged partners.” So it’s possible that poly relationships appear worse in some ways only because poly people are more likely to have a large age gap with their partner.

Importantly, she found that primary partners in polyamorous relationships have about as much sex as people in monogamous relationships. I don’t think we should conclude from this that polyamory doesn’t drain attention. The other observed monogamous relationships don’t necessarily reflect how the polyamorous people would behave if they were in monogamous relationships. I suspect they would have even more sex in a monogamous relationship, and that their polyamory is driven in part by a desire for more sex to begin with.

Before proceeding to summarize, there’s another benefit to permitting polyamory I should mention. It might be that polyamorous people are more likely to cheat on a monogamous partner. If you permit polyamory, you might, in effect, be separating potentially bad partners out of the pool of monogamous ones. Exclusively monogamous people don’t want to partner with cheaters, and if polyamorous people are more likely to cheat while monogamous, it’s better for them to enter a dating pool of other polyamorous people. It seems impossible to check whether this is true or not, but it does seem likely to be true for the same reason gay people forced into straight relationships might cheat more often than if they were in a gay one.

The question we really need to ask is this: from a societal perspective,² do the benefits of permitting polyamory outweigh the costs?

The benefits of permissiveness toward polyamory are:

• The benefits accrued to some people who are in a polyamorous relationship and enjoy it, beyond those they would enjoy from their next-best alternative (whether monogamy or singlehood). Some people just like having multiple partners.

• Better matching, but this probably doesn’t matter much. You might be able to gather more information about who your primary partner should be by being in a polyamorous relationship and bringing in other people. Opening up a relationship might be how both partners discover their next one. Ironically, polyamory has probably assisted the creation of monogamous relationships at times.

• Potentially sorting cheaters out of the pool of monogamous people.

The costs are:

• Good relationships can be ruined by one partner attempting to open up the relationship. I suspect that usually these relationships are not good, but this is still plausible.

• People in polyamorous relationships might just be stupid. Monogamy could be “natural” to people. Their relationships tend to be shorter, which is evidence to this point (though there are alternative explanations I prefer).

The costs seem small in comparison to the benefits, so I don’t think the benevolent solution is to make this verboten. The vast majority of people in monogamous relationships have an implicit understanding that you don’t get to “open up” the relationship. Polyamorous people don’t appear to be particularly stupid, and seem to enjoy their relationships about as much as monogamous people, as seen in Aella’s survey.³

Still, I suspect that a strictly monogamous majority would gladly use its social power to prohibit polyamory for their own benefit, because they have to deal with part of the costs of it and don’t benefit too much. That their partner might be less likely to cheat as a consequence of permitting polyamory is the only benefit to a strictly monogamous person. The thought of their partner saying “I’ve been thinking about opening up our relationship” weighs more heavily on the mind. It’s especially easy to sidestep your own empathy and talk about the evils of polyamory, because you can just say “This isn’t a natural or necessary way to live anyway, so why should I feel bad if these people are ‘oppressed’?”

And there’s some truth to that! Gay people are gay. Polyamorous people just have strong preferences for more than one partner. The more fundamental features of a relationship are still there if you’re a polyamorous person forced to live in a strictly monogamous world. So I’m not too worried about people stopping the formation of polyamorous relationships, though I am worried about people shaming others for being in healthy polyamorous relationships. Not cool.

1. Strictly defined, I would say cheating means explicitly dating or engaging in intimate acts like kissing or sex with someone while you are partnered with someone else who has not permitted it. Polyamory is the same thing but with consent.

2. i.e., considering the benefits and costs to everyone.

3. This was not an unbiased random sample of the whole population, but we don’t really have a better option.