Though some ancient civilizations permitted polygamy, or multiple wives, the idea of monogamous marriage has been deeply rooted in Western society since the time of the Ancient Greeks. Although monogamous Hellenic men were free to have their way with their male and female slaves.Monogamy quickly became the norm—and social norms influence our psychology. The process of adhering to social rules and punishing rule violators tickles the reward circuits of our brains. Some studies suggest that each time you think to yourself that polyamory is icky, an oxytocin molecule gets its wings.

via Multiple Lovers, Without Jealousy – The Atlantic.