As some of our American readers may know the California Supreme Court has recently ruled that men and men in California can get married. This has led a number of people (Krauthammer) to speculate that polygamy is right around the corner. (Volokh) Most of the arguments about the meaning of marriage make a lot of arguments (usually pretty bad ones) based on evidence from “marriage through history.” Very few people seem aware of how -very-different modern companionate, equal marriage is from the various forms of usually economic and always unequal relationships that have existed throughout human history. It is true that throughout most of history “Bill and Ted are in love so they should get married” was not considered a good argument, but the same can be said of “Susan and Ted.” This makes it tricky to get much useful ammunition for contemporary debates from historical evidence unless you twist the history quite a bit. Still, it is sort of interesting to thing about the disappearance of polygamy, which was pretty common in upper classes around the world before the modern era, and specifically about the end of polygamy in China.
Although an awful lot has been written about attacks on the traditional family in Republican China there has been relatively little on polygamy as a specific issue. I think this is true of Japan as well. Polygamy as such was not really singled out much as one might expect. Nevertheless it died out rapidly. Polygamy seems not to have been a major issue for early feminists like He Zhen although they did mention it. For them the big issue in marriage was equality, which of course does not mix with polygamy. If a husband in a modern marriage gives his wife “everything” (particularly emotionally) how can he do so for more than one woman? ((A parent can give ‘all’ their love to more than one child, but of course women are not (any longer) children)) That polygamy was out would seem to almost go without saying with modern ideas of marriage. ((To the extent polygamy exists at all today it is in places or subgroups without much of an idea of gender equality. The examples used in discussion are always one man with more than one woman, since while that would fit in with some traditional ideas the opposite would just be bizarre.))
It might also matter that most scholarship on Chinese feminism has wanted to focus on women. I would assume that the people making the decision to not have a second wife were men. Being a secondary wife was never regarded as a good thing, so for the educated women who read and wrote for the early radical journals becoming a secondary wife would not really be a threat. The poorer women who might have ended up secondary wives were not reading He Zhen in 1907 or making many other choices about their lives. ((Class and consumption sort of fit here too. In a modern relationship both spouses should be equal in their use of the joint assets. How can you do that with too many of one type of spouse? )) Well-off men were presumably making the decision not to have secondary wives. One presumes that whatever pressure their families may have put on them to have a first wife that fit with traditional ideals (Lu Xun did it) there would be much less pressure to have a traditional secondary wife if they did not want to. Why and how secondary wives became unfashionable (or were replaced with mistresses) would be an interesting study.
I can’t really speak to the legal issue in the U.S. (what legal arguments would the state have to prevent one woman from marrying two men at the same time or whatever) but as a social issue it seems to be a non-starter. Polygamy is tied to a class structure and view of marriage that just don’t exist any more and never will.