It's clear that there are many differences of opinion here, as well as many different personal experiences. Putting my work-hat on for a moment though (I'm a scientific researcher), I'm curious to know one thing: what does it matter? In other words, what do you think the implications are? If polyamory is, as some of you believe, an orientation or a sexual identity, does that give it more impact or traction within society? If it's a choice, should it be something we educate others upon, so that people are aware of it as an option? Does an answer give polyamory a certain status in your eyes? If so, in what way?
Basically, what do we do with this concept? Why is this an important question?
The reason I ask is that I wonder if polyamory faces the same kinds of acceptance problems as something like having a minority sexual orientation, even if it's actually a different kind of thing altogether. To explain, if I consult my own experience I would say that for me polyamory not an identity/orientation: it is a relationship style I have chosen because it better fits the needs of my personality type, my current life-style, Nina's personality type, her current life-style, and the relationship that we have built together. If any of those things were to change, then I would re-evaluate whether a polyamorous relationship were still a good fit for me. It doesn't feel like a thing I cannot influence with conscious choice, like who I am sexually attracted to is. For me, that's an orientation. I don't 'choose' who I find attractive, but I do choose whether and when I act on an attraction. I have the hots for who I have the hots for, but I decide for myself whether I want to pursue people one at a time or in parallel, and if I've already agreed to be in a monogamous relationship for some reason, then I need to renegotiate that agreement with my current partner and take their preferences into account too.
You can see I'm drawing a distinction between my sexual orientation (being something I don't feel I choose) and being in a polymorous relationship (being something I might prefer, but ultimately decide upon with a partner). However, unlike many who see sexual orientation (gay, hetero, bi, pan, etc) as strongly innate part of your personhood, I have *actually* experienced it as something that can shift quite dramatically over time - and this complicates things a little. The fact that a person's sexuality (mine, in this case) can change over time implies to me that it's not strongly innate at all, but rather is something that straddles that middle ground between choice, conditioning, and natural instinct.
If I talk about sexual orientation being a flexible, malleable thing however, I rub up against opposition both internally (it feels like a dangerous thing to admit to) and from friends in the LGBT community. It seems that in having the whole world think that being LGBT is not a choice, we somehow earn some protection from those who have ideas that being LGBT is wrong. If we contradict that claim, we risk reducing societal acceptance and basically a return to LGBT-hood being seen as a pathology of some kind. Does polyamory fall into this same camp do you think? Is even asking this question ('is polyamory a sexual identity, just like being queer?') perhaps opening a pandoras box that we don't want to delve into?