Thanks to Facebook, the topic of non-monogamous relationships has been crossing my screen with some regularity lately. One of the first instances involved the topic of cuckoldry: cases in which a man's committed female partner will have with, and become by, another another man, often while the man in the relationship is fully aware of the situation; perhaps he's even watching. The article discussing the matter came from Playboy which, at one point, suggested that cuckoldry is the second most common type of porn sought out in online searches; a statement that struck me as rather strange. While I was debating discussing that point - specifically because it doesn't seem to be true (not only does cuckold porn, or related terms, not hold the number 2 slot in PornHub's data searches, it doesn't even crack the top 10 or 20 searches in any area of the world) - I decided it wasn't worth a full-length feature, in no small part because I have no way of figuring out how such data was collected barring purchasing a book

Source: Flickr/GotCredit

The topic for today is not cuckoldry per se, but it is somewhat adjacent to the matter: open relationships and polyamory. Though the specifics of these relationships vary from couple to couple, the general arrangements being considered are relationships that are consensually non-monogamous, permitting one or more of the members to engage in sexual relationships with individuals outside of the usual dyad pair, at least in some contexts. Such relationships are indeed curious, as a quick framing of the issue in a nonhuman example would show. Imagine, for instance, that a researcher in the field observed a pair-bonded dyad of penguins. Every now and again, the resident male would allow - perhaps even encourage - his partner to go out and mate with another male. While such an arrangement might have its benefits for the female - such as securing paternity from a male of higher status than her mate - it would seem to be a behavior that is quite costly from the male's perspective. The example can just as easily be flipped with regard to sex: a female that permitted her partner to go off and mate with/invest in the offspring of another female would seem to be suffering a cost, relative to a female that retained such benefits for herself. Within this nonhuman example, I suspect no one would be proposing that the penguins benefit from such an arrangement by removing pressure from themselves to spend time with their partners, or by allowing the other to do things they don't want to do, like go out dancing. While humans are not penguins, discussing the behavior in the context of others other animals can remove some of less-useful explanations for it that are floated by people (in this case, people might quickly understand that couples can spend time apart and doing different things without needing to have sex with other partners).

The very real costs of such non-monogamous behavior can be seen in the form of psychological mechanisms governing sexual in men and women. If such behavior did not reliably carry costs for the other partner, mechanisms for sexual jealousy would not be expected to exist (and, in fact, they may well not exist for other species where associations between parents ends following copulation). The expectation of seems to be the key factor separating pair-bonds from other social associations - such as and kinship - and when that expectation is broken in the form of , it often leads to the dissolution of the bond. Given that theoretical foundation, what are we to make of open relationships? Why do they exist? How stable are they, compared to monogamous relationships? Is it a lifestyle that just anyone might adopt successfully? At the outset, it's worth noting that there doesn't seem to exist a wealth of good empirical data on the matter, making it hard to answer such questions definitively. There are, however, two papers that discuss the topic I wanted to examine today to start making some progress on those fronts.

The first study (Rubin & Adams, 1986) examined martial stability between monogamous and open relationships over a five-year period from 1978-1983 (though precisely how open these relationships were is unknown). Their total sample was unfortunately small, beginning with 41 demographically-matched couples per group and ending with 34 sexually-open couples and 39 monogamous ones (the authors refer to this as an "embarrassingly small" number). As for why the attrition rate obtained, two of the non-monogamous couples couldn't be located and five of the couples had suffered a death, compared with one missing and one death in the monogamous group. Why so many deaths appeared to be concentrated in the open group is not mentioned, but as the average age of the sample at follow up was about 46 and the ages of the participants ranged from 20-80, is possible that age-related factors were responsible.

Concerning the stability of these relationships over those five years, the monogamous group reported a separation rate of 18%, while 32% of those in the open relationships reported no longer being together with their primary partner. Though this difference was not statistically significant, those in open relationships were nominally almost twice as likely to have broken up with their primary partner. Again, the sample size here is small, so interpreting those numbers is not a straightforward task. That said, Rubin & Adams (1986) also mention that both monogamous and open couples report similar levels of jealously and in those relationships, regardless of whether they broke up or stayed together.

Source: Flickr/George Kelly

It's difficult to determine how many couples we ought to have expected to have broken up during that time period, however. This study was conducted during the early 80s, and that time period apparently marked a high-point in US divorce frequency. That might put the separation figures in some different context, though it's not easy to say what that context is: perhaps the monogamous/open couples were unusually likely to have stayed together/broken up, relative to the population they were drawn from. On top of being small, then, the sample might also fail to represent the general population. The authors insinuate as much, noting that they were using an opportunity sample for their research. Worth noting, for instance, is that about 90% of their subjects held a college degree, which is exceedingly high even by today's standards (about 35% of contemporary US citizens do); a full half of them even had MAs, and 20% had PhDs (11% and 2% today). As such, getting a sense for the demographics of the broader community - and how well they match the general population - might provide some hints (but not strong conclusions) as to whether such a lifestyle would work well for just anyone.

Thankfully, a larger data set containing some demographics from polyamorous individuals does exist. Approximately 1,100 polyamorous people from English-speaking countries were recruited by Mitchell et al (2014) via hundreds of online sources. For inclusion, the participants needed to be at least 19 years old, currently involved in two or more relationships, and have partners that did not participate in the survey (so as to make the results independent of each other). Again, roughly 70% of their sample held an undergraduate degree or higher, suggesting that the more sexually-open lifestyle appear to disproportionately attract the well-educated (that, or their recruitment procedure was only capturing individuals very selectively). However, another piece of the demographic information from that study sticks out: reported sexual orientations. The males in Mitchell et al (2014) reported a heterosexual orientation about 60% of the time, whereas the females reported a heterosexual orientation a mere 20% of the time. The numbers for other orientations (male/female) were similarly striking: bisexual or pansexual (28%/68%), homosexual (3%/4%), or other (7%/9%).

There are two very remarkable things about that finding: first, the demographics from the polyamorous group are divergent - wildly so - from the general population. In terms of heterosexuality, general populations tend to report such an orientation about 97-99% of the time. To find, then, that heterosexual orientations dropped to about 60% in men and 20% in women represents a rather enormous gulf. Now it is possible that those reporting their orientation in the polyamorous sample were not being entirely truthful - perhaps by exaggerating - but I have no good reason to assume that is the case, nor would I be able to accurately estimate by how much those reports might be driven by social desirability concerns, assuming they are at all. That point aside, however, the second remarkable thing about this finding is that Mitchell et al (2014) don't seem to even notice how strange it is, failing to make mention of that difference at all. Perhaps that's a factor of it not really being the main thrust of their analysis, but I certainly find that piece of information worthy of deeper consideration. If your sample has a much greater degree of and incidence of non-heterosexuality than is usual, that fact shouldn't be overlooked.

Source: Flickr/Sean Savage

In general, from this limited peek into the less-monogamous relationships and individuals in the world, the soundest conclusion one might be able to draw is that those who engage in such relationships are likely different than those who do not in some important regards; we can see that in the form of educational attainment and in the present data set, and it's likely that other, unaccounted for differences exist as well. What those differences might or might not be, I can't rightly say at the moment. Nevertheless, this non-representativeness could well explain why the polyamorists and monogamists have such difficulty seeing eye-to-eye on the issue of exclusivity. However, sexual topics tend to receive quite a bit of moralization in all directions, and this can impede good scientific progress in understanding the issue. If, for instance, one is seeking to make polyamory appear to be more normative, important psychological differences between groups might be overlooked (or not asked about/reported in the first place) in the interests of building acceptance; if one views them as something to be discouraged, one's interpretation of the results will likely follow suit as well.

References: Mitchell, M., Bartholomew, K., & Cobb, R. (2014). Need fulfillment in polyamorous relationships. Journal of Sex Research, 21, 329-339.

Rubin, A. & Adams, J. (1986). Outcomes of sexually open marriages. The Journal of Sex Research, 22, 311-319.