Talking about in humans specifically.
I mean, from a practical, survival kind of standpoint, having more than 2 people in a relationship seems really beneficial. But there also seems to be a number, a tipping point as it were, where the relationship would be too large and clunky, at least with regards to intimate connections running smoothly. I imagine at that point the group would splinter off somehow and form a new family.
The problem, it seems, with expanding your relationship is attracting people who are truly going to be committed to the concept of "all of us" and not "you and me". Most of us have been raised in a society that promotes rugged individualism (either/or thinking) over a more group-centered (tribal) psychology, right? Add into that all of our fears and insecurities and you have a train wreck.
Being polyamorous seems like a reaching back to something both simpler and more complicated that could be found in our species ancient history, but I wonder if we've come to far in the direction of imagined growth and prosperity for many of us to be able to evolve our relationship style and beliefs into that form again?
I've always believed that polyamory was the most realistic approach to loving and bonding that could exist. Since I was 16 years old I've believed that but, of course, been in nothing but strictly monogamous relationships, which included all of the joys and horrors of such a high-pressure construction. Like, our entire concept of love and romantic bonding is built around the idea that 2 people meet, fall in love, get married and have a baby; almost every romantic book, play, novelization, song, painting, poem, music video, article, lecture, workshop, website, etc. is focused on this idea, right? But I've always thought it was just silly to think that love, with all its complexities and mysteries and miracles, could be squeezed into a single connection with one other human being and put under wraps until that relationship ended and then it was applied to a new partners and so on.
Its cool having this forum so that we can see what other people think and are experiencing.