I want to study this a bit more, but for right now, thinking about what makes humans different from the many creatures that don't mate for life...I find that we spend a majority of our lives trying to develop trust, so even if we believe that variety is the spice of life and it would be nice to love a bunch of a people at once, we're busy trying to find AT LEAST one being in the sea of billions that is willing and able to stay on our current. What a long sentence. So maybe monogamy is a defense mechanism. Or maybe being surrounded by a bunch of strangers is an aphrodisiac, and polygamy is a legit response to that.
Do bugs have to formulate trust within this orb of psychosocial chaos before they fuck? What makes the ducks, wolves and beavers choose a version of matrimony versus the butterflies that don't? And even further, what's with the trend of the male species getting around while the female species remains more conservative? Surely so many factors come into play for every group of creatures--environment, biology, etc. How much do nonhumans deal with jealousy and possessiveness? The questions are endless. Personally, I am a sloth and can't tend to too many gardens at once. However, the ability to understand and nurture a living being wholly, for as long as necessary, is not something I want to be tightfisted about either.
I recognize that our world thrives off of the spreading, not the concealment of light. We just have to find an efficient balance...Based on my own energy, I like to think that loving AT LEAST one person completely will have a butterfly effect on the universe, so I focus on my swan-life and its ripples. I don't think monogamy equates to monotony--not if that closeness is used to stimulate creativity. But I'm also not gonna sleep on relationships that are more inclusive while expansive because I know they, too, have something to offer. I know that if I or my partner ever felt limited in exploration or that we were suppressing natural urges, we'd put that in the open.