I think poly is a choice. Just like every other relationship structure. I also happen to believe that loving more then one person at a time is something everyone on the earth is capable of. But relationship structure is a choice. I don't choose to love multiple people at the same time but I do choose to peruse and work on relationships with multiple people at the same time. That is a choice I get to make.
I think it's important and powerful to make this choice when it isn't as supported by our culture. But no I was not born this way. I'm choosing to live my life this way. Granted it might be that I wouldn't be able to be as happy if I was forced to be monogamous but monogamy is just a structure and culture builds structures.
I do believe that some people are more suited for poly but I always bristle at discussions about "hard wiring" because I believe the way we make relationship is built off of what we see around us either by excepting or rejecting or not even realizing that there are other options.
We build the way relationships look. I choose this. I don't think that should make it any less important, in fact, in a way I think it's more important then some gene that is forcing us to be some way we can't help. We GET to choose. And the more information out there, the more out people, the more examples of poly in the world the easier it gets for people to see there are options. And options are good.