A while back, I had posted on polyamoury, and, as I watch news and other discussions on a number of things, I think maybe a bit better chance to to talk about it is here. Namely: Why would someone go that route? Why not stick with the “traditional” one partner relationship? Sure, I could argue the anthropological point that most cultures are polygamist, and monogamy is actually pretty much only truly seen in post-Christianity Western Societies, and in societies trying to emulate them. Or I could argue all the stuff that scientists say to point out that monogamy is not how Humans are engineered. But, that really doesn’t address the big question: Why would you choose polyamoury over the single partner relationship?
One would argue that the classic, single partner relationship leads to greater emotional intimacy, that, because they are the “tradition” that makes them better, or a wide variety of other arguments. You could argue that cult leaders preach polygamy, and since cults are bad, anything they advocate is bad, as well. You could even use a bunch of religious reasons(which are, of course, completely invalid if the person you are arguing those reasons to does not follow your religion). But, those are all reasons why not. In addition to all those, the purpose of Marriage in the West has traditionally been to insure legitimacy of children, and to secure “proper” lines of succession and inheritance. In short, it was all about property and how it passes along. But, again, that is all about a reason why not.
The choice is always going to be made for a variety of reasons. Not all of those are going to be logical, but, when dealing with relationships, logic is not always going to be a big factor. One simple reason is that the additional person or persons bring something more to the relationship. Someone with an extremely submissive partner, for example, might have another partner who is more dominant. Or, maybe, one partner is better at emotional support, while the other is better at helping out with a variety of other things the one who provides emotional support cannot, and the two form a partnership to help the third partner.
Another reason could be practicality and ethics. Say two of the partners very much want children, but one of them suffers from some genetic disease that would like be passed on to any children he/she was a parent of. Does this one leave the other partner to prevent that? Do they adopt? What if they have another person who is emotionally capable of working through the reality of a triple relationship, who also wants children? This could lead to a beneficial partnership, making all three happy, and making sure that any child is in a better position for support, and keeps both biological parents involved.
Of course, other reasons amount to:no-one is really a one person person. And, more importantly, they are not prone to jealousy. If they can work with others, communicate, and be honest, then polyamourous partnerships could be more natural, and more comfortable for all involved, then a more traditional two-partner relationship, just because it is more what they want. Frankly, there is not any one reason why. However, as much as there are reasons not to, for those who have functional group relationships, those reasons of “why not” are not important. The reasons why they work are just as inscrutable as to why the more “traditional” kinds of relationships work or fail.