Why Are So Many Rationalists Polyamorous?

Originally posted at Living Within Reason.

Last week, Jacob Falkovich, of the Putanumonit blog, put up a post trying to figure out why rationalists are disproportionately polyamorous. He notes that about 5% of Americans engage in consensual nonmonogamy, while 17% of Americans in the 2014 Less Wrong survey indicated that they did. My expectation is that the number for both is slightly higher today. In service of this goal, Falkovich developed several theories and surveyed a number of his readers. His results ended up inconclusive.

Since this involves the intersection of the two themes of this blog – rationality and nonmonogamous relationships – I thought I would offer my own theories about why this might be the case. I don’t have any survey data, but if anyone is planning on doing a survey, you may want to include some questions evaluating these theories.


Rationalist try to be rational about everything, so we also try to be rational about relationships. Relationship anarchy is my attempt to derive a rational relationship style from first principals.

While there are some good reasons to be monogamous, anecdotally, the most common justifications I hear for monogamy are jealousy-related. People don’t want open relationships because they would be jealous of their metamours (and often, their partners). But jealousy is just an emotion, and rationalists have a tradition of distrusting emotions. Falkovich somewhat addressed this in his first theory – overcoming intuitions:

A core tenet of Rationality is that what feels true is not necessarily what is true. What feels true may simply be what is pleasant, politically expedient, or what fits your biases and preconceptions. The willingness to entertain the idea that your intuitions about truth may be wrong is a prerequisite for learning Rationality, and Rationality further cultivates that skill.

Unfortunately, Falkovich’s analysis is frustrated by the lack of variance in his survey data on whether people overcome their intuitions. I have a feeling that this result was limited somewhat by the survey questions, which asked participants to rate how much they trusted their intuitions and whether they ever significantly changed their emotions through analysis and introspection.

The difficulty is that there are a whole host of cognitive biases encouraging us to believe that yes, of course we trust our cognition more than our intuition, but that can easily just be motivated reasoning. Some people will admit that they “go with their gut,” but that sort of thing is frowned on in the rationality community, so it doesn’t surprise me that most of the participants claimed to trust their cognition more regardless of whether that’s actually the case.

The small amount of variance in Falkovich’s survey was highly correlated with polyamory, so that lends some credibility to the argument that rationalists choose polyamory because they do not reflexively trust their feelings of jealousy.


If you spend enough time around my rationalist friends, they will start talking about prisoner’s dilemmas. It’s inevitable. Scott Alexander has a whole game theory sequence. Rationalists love game theory, and in particular, they love coming up with coordination strategies to turn things from zero-sum to positive-sum games.

Monogamy is a zero-sum game. Each person gets one partner, and once that partner is taken, they are removed from the dating pool for everyone else. There is no sharing, coordination, or trading. There are no complicated strategies that can be optimized. In other words, it’s not interesting to rationalists.

Nonmonogamy, properly coordinated, is a positive-sum game. Multiple people can partner with the same person and unless they always want undivided attention at the exact same times, they can coordinate so everyone is better off. Nonmonogamy allows parties to, for example, have a date with one partner while their other partner is busy, spend time with multiple partners at the same time, and coordinate to compensate for imbalances in sex drive. Parties rarely want exactly the same thing from their partners, so there are usually large opportunities for emotional arbitrage.

I strongly suspect that this impulse toward coordination and creating positive-sum interactions underlies a substantial amount of rationalists’ preferences for nonmonogamy.


On Falkovich’s survey, 78% of the respondents where heterosexual men. 11% were women interested in men. That’s a 7:1 ratio. Other surveys of the rationalist community have indicated similar gender and sexuality breakdowns.

In the Robert Heinlein novel The Moon is a Harsh Mistress, the moon is originally used as a penal colony, and as a result has a population that is mostly men and few women. The result is that, out of necessity, the society developed to allow women to date multiple men. When there are multiple heterosexual men for each woman interested in dating them, you either have nonmonogamy or you have a lot of lonely men.

A similar thing may be happening with the rationalist community. It’s not the moon, so rationalists are free to date outside of the community, but people often want to date like-minded people. Most rationalists would probably prefer to date other rationalists. Rationalist women likely have multiple suitors all the time, and may find more than one appealing. Unless they are particularly high-status, rationalist men then face the choice of embracing nonmonogamy, dating outside the community, or not dating at all. Notable also is that most of the high-status men in the rationalist community are nonmonogamous. Under those constraints, nonmonogamy may be the ideal choice for many of us.

Further Study

Ozy is currently recruiting nonmonogamous survey participants. If you are nonmonogamous, please consider taking the survey. I have never done any kind of survey design, so I do not know how one would test the above theories. However, if someone is planning on doing a survey of the rationalist community and is interested in this question, I encourage you to consider the above and perhaps try to design some questions to test its accuracy.