From William Tucker's article entitled "Polygamy and Me" in today's American Spectator:
"Both high-status men and low-status women are liberated by polygamy. As the old saying has it, men "date down and marry up." With polygamy you can do both. Meanwhile, the losers are: 1) high-status women, who must share their mate with lower-status females, and 2) low-status men, who don't get to mate at all.
It's that last one that causes trouble. Every society and species that practices polygamy is plagued with a "bachelor herd" of unmated males who are very unhappy with their lot. Competition among males becomes much more violent because the stakes are so high. You either score with a couple of females or you don't mate at all. Male fruit flies artificially bred to be monogamous have proved to be much less aggressive with other males. Take away that monogamous contract and your peaceful society disappears with it."