One point of view is that the U.S. is currently running under semi-polygamous norms. A stunning proportion of U.S. adults are "single," but that doesn't necessarily mean they're not having sex.
Of course---partners are not evenly distributed, leading to numerical outcomes more akin to polygamy than polite society might pretend.
Of course---partners are not evenly distributed, leading to numerical outcomes more akin to polygamy than polite society might pretend.