Annalise, the main thing that differentiates us from all other animals is the structure of our brains. We have a neocortex, no other animal does. This difference does many things for us, but one thing it does is removes sex from the realm of the merely instinctual and drive-based. We are no longer creatures who breed when "in heat", but we can bring our tremendous creativity and ingenuity to lovemaking in a way no other animal can. Therefore, for us, sex is not just about procreation, and it is also most definitely NOT a mere physical "need", like hunger. The reason the D rate is so high and people practice serial monogamy is that most people don't understand how marriage actually works, and they bail at the first sign of conflict. Many, many people who get divorced COULD learn to work through their problems, and avoid D, but they either don't learn what they need to in time, or they just don't care enough. The prevalence of serial monogamy in today's society does NOT mean that REAL monogamy isn't workable... it simply tells us something very unflattering about our present society...
