Most polygamous societies were still predominantly monogamous - the majority of men had only one wife, multiple wives was generally something reserved for the w

Most polygamous societies were still predominantly monogamous - the majority of men had only one wife, multiple wives was generally something reserved for the wealthy elite. For example, even at the height of Mormon polygamy in Utah, only 15-20% of Mormon families were polygamous, the other 80%+ of Mormons (mostly) believed in it but didn’t practice it. I think the argument is that putting constraints on individual sexual freedom promotes social stability in the long-run; the existence of constraints is more important than their precise details.