According to the 2014 LessWrong Survey Results, 15.1 % of the LessWrong community prefers polyamorous relationships to monogamous ones. If you don't know what polyamory is, it's been described as "consensual, ethical, and responsible non-monogamy. (Source). This excludes (formerly) monogamous relationships where one party is "cheating", i.e., engaged in an additional sexual or romantic relationship in secret. Semi-monogamous, or "monogamish", marriages and relationships may be count as polyamorous in the minds of some, but may be eschewed by the couple in question themselves. Among LessWrongers and almost all secular crowds, at least, "polyamory" is also not the same as the common thought of "polygamy", usually polygyny (one man, many women), which is practiced by some religious sects, and adheres to norms not shared by the polyamorous.

Anyway, I don't recall the specific column, but I've read letters to sex columnist Dan Savage about polyamorous people who believe there desire and preference for polyamory is biological or hard-wired, rather than merely being a choice. I recall Dan Savage being somewhat skeptical because "polyamory as hardwired preference" doesn't currently seem to have a basis in science. I'm skeptical. However, there is a history of sexual or gender minorities (who have faced discrimination and prejudice) to also faced backlash they were making lifestyle choices, rather than engaging immutable biological preferences. However, it's commonly accepted among scientists now homosexuality is not a choice, and research goes on in determining exactly what are its bases in biology, whether they be genetic, or due to prenatal hormones, or something else. In recent years, brain scans reveal patterns in the brains of transgender persons more closely match the patterns of the gender/sex they prefer, rather than the gender/sex they were assigned at birth. (More details).

I'm aware I could have a historical bias, where the culture of the sexual majority assumes it's way is the only "natural" or actual way humans can possibly relate to each other sexually, until science comes along, and debunks those assumptions. By merely questioning the notion preferences for polyamory have a basis in psychobiology rather than being a lifestyle choice indicate I'm privileging the hypothesis? Should I abandon confidence in the assumption polyamory has no basis in biology?

If you have an opinion on this matter, especially one informed by some kind of formal studies, please share.

The issue of how to approach this question is summed up by a Slate article, "Is Polyamory A Choice?":

Meanwhile, there are some people whose innate personality traits make it very difficult to live happily in a monogamous relationship but relatively easy to be happy in an open one. Given the persecution heaped on gays in most of the world in recent generations, and the relative difficulty of “passing,” there are probably few people who would choose that identity unless they could not find happiness in straight life. So, sure, there may be a larger fraction of non-monogamists for whom their unconventional relationship is “optional” or “a choice.” But there are almost certainly also some “obligate” non-monogamists who would never feel emotionally satisfied and healthy in a monogamous relationship, any more than a gay man would be satisfied and healthy in a straight marriage.

I would have cited a scholarly source, but I don't have the time now, and I'm guessing they're hard to find. Based on how the author of the article didn't cite any academic sources, and merely stated he hopes there will be more scholarship on this issue in the future, I'm guessing he couldn't find (m)any good studies, either.