This started out as an entirely different post, but sometimes you have to go with the flow. So it ended up as a collection of studies and numbers about various relationship models, because the results were quite surprising.
In my earlier postings, I was quite critical of “the” western relationship model, the monogamous relationship. Then I set out to find facts to support my position. I thought that would be easy, given how everyone decries the horrible divorce rates, the increasing demand for marriage councelling and other evidence that the model is not really working out all that well now that social pressures to keep up the pretext are dropping.
But, it turns out that it isn’t quite that simple.
First off, there is an important distinction to make, between various types of non-monogamous relationship models. Other articles go into depth about the differences between polyamory, swinging, open relationships and other overlapping terms. For my purposes, I want to single out love/romance based models (polyamory) and sex-based models (open relationships, swinging) with the simple differentiating point that the first kind has three or more permanent members, while the other kinds have two permanent members and changing temporary members. In this continuum, monogamy is, of course, one step further with two permanent and zero temporary members.
It turns out that there is a bit of a body of research for polyamory, and a small bit for open relationships. Well, actually there is quite a bit, but the majority appears to focus on gay, lesbian and bi-sexuals. I’ve ignored this, as there is evidence indicating that especially among gays the evaluation of monogamy vs. polyamory is quite different from heterosexual couples. And I will leave gay topics to those who know what they’re talking about.
The most comprehensive scientific document I could find on polyamory is titled What therapists should know about Polyamory. It’s worth a read in its entirety if you are the least bit interested in the topic. The crucial parts I want to pick out are these:
In 1976, Knapp administered a battery of standardized psychological assessment measures to a sample of polyamorous couples (Knapp, 1976). No significant differences were found between the couples in her sample and the general population norms. “That is, neither group was particularly neurotic, immature, promiscuous, maladjusted, pathological, or sexually inadequate…
[…]Twitchell (1971, 1974) applied the Minnesota Multiphasic Personality Inventory (MMPI) to several samples of persons with high degrees of involvement in nontraditional sexual re- lationships and control groups, and found no significant differences between the “sexually liberal” group and the controls.
[…]Buunk (1980) found that couples with open marriages in the Netherlands were normal in terms of marriage satisfaction, self-esteem, and neuroticism. Spanier’s (1976) Dyadic Adjustment Scale was used to compare sexually open couples with sexually exclusive ones (Rubin, 1982), and no dif- ferences were found in adjustment or happiness between the two groups. “Nothing in this data argues for the view that sexual openness or exclusivity, in and of themselves, make a difference in the overall adjustment of a married couple.”
[…]A follow-up study (Rubin & Adams, 1986) found that after several years, there was no significant difference in marital stability (i.e. breaking up vs. staying together) between those couples who had been polyamorous versus those whose marriages had been exclusive.
Wow. I didn’t see that coming. This and additional comments and studies mentioned draw a picture contrary to what I was expecting: That both polyamory and monogamy are very much alike in their effects on the participants. If you make the happiness (and other mental states) of those involved the measurement, monogamy is an equal to polyamory.
For open relationships, the material is a bit harder to find, but results exist, like the Outcomes of sexually open marriages study. Which also finds:
no statistically significant difference in marital stability was found.
I have not been able to find actual evidence that non-monogamous relationships are in any measurable way superior to monogamy. And it’s not for not trying.
There is still criticism left, however. Monogamy is one of those built-in conflicts of our species, given that evidence points to polygamy as the biological norm (and looking at our relatives in the animal kingdom, that’s not a big surprise) and monogamy is more of a social than a biological desire. And of course, there’s the reality which for most of the west is that we have serial monogamy, affairs and jealousy.
The most serious criticism in my eyes is that if a polyamorous relationship fails, then more often than not the relationship model is blamed, even though the studies linked to above indicate that there is no truth to that. When a monogamous relationship fails, it is rare indeed for the blame to be put on monogamy.
But still, on the facts, monogamy does surprisingly well. And the same evidence I linked to above also indicates that polygyny (i.e. socially sanctioned polyamory) leads to more violence within the society and monogamy my be the socially better option.