GM. The main benefit of monogamy is that it can provide a stable and healthy environment for raising children. The benefit of polyamory is that it provides variety which can keep relationships exciting. The human brain is constantly looking for novelty and we are wired to reproduce with different partners. It’s an evolutionary instinct that increases the chances of offspring survival. If you had all of your children with a genetically weak man, and you committed to him, your offspring may die and you may miss the chance to pass down your own genetics.