On Monogamy

A unique feature of Western Civilization is the practice of socially imposed monogamy.

In a 2013 article, Dr Kevin MacDonald writes:

But the issue of polygamy has already been before the Supreme Court, and the opinion—which upheld monogamous (heterosexual)  marriage as the only legitimate form of marriage—is of contemporary interest because of how it defended traditional monogamous marriage. [...] It asserts the uniqueness of European civilization—that its culture and traditions are quite separate from those of Asia and Africa and that monogamy is a defining feature of the West. In this the court is quite right. Traditional European culture is the only civilization where monogamy is the norm. [...] The court went beyond an argument from tradition, proposing that the social norm of monogamy benefits society because it is more compatible with individual freedom and non-despotism. [...] I have argued that monogamy is part of a suite of traits underlying Western individualism, including the nuclear family, exogamy and a de-emphasis on the extended kinship group.

MacDonald elaborates on differential marital patterns between civilizations in a 2002 issue of The Occidental Quarterly:

Traditional civilizations around the world, including those of China, India, Muslim societies, the New World civilizations, ancient Egypt and ancient Israel, often had hundreds and even thousands of concubines. [...] Western societies beginning with the ancient Greeks and Romans and extending up to the present have had a powerful tendency toward monogamy. Ancient Rome had a variety of political institutions and ideological supports that tended toward monogamy. The origins of socially imposed monogamy in Rome are lost in history, but there were several mechanisms for maintaining monogamy, including laws that lowered the legal status of offspring born outside monogamous marriage, customs opposing divorce, negative social attitudes toward non-conforming sexual behavior, and a religious ideology of monogamous sexual decorum. Variations of these mechanisms have persisted throughout Western history down to the present.

Monogamy was a practice that the Romans shared with Germanic peoples, as noted in Tacitus' Germania:

The marriage bond is strict, and no feature in their mode of life is more creditable to them  than this. Unlike the great majority of barbarians, they are content with one wife: very few of them have more than one, and these few exceptions are not due to wantonness; they are cases of men of high rank, to whom several matrimonial alliances have been offered from motives of policy.

In support of his claim about the centrality of the monogamous family to the emergence of Western culture, MacDonald refers to a 2008 paper by Wolfgang Haak et al, exploring the newly discovered Corded Ware burials outside Eulau, Germany; the same team of researchers first publishing solid genetic evidence supporting the Steppe hypothesis of the Proto-Indo-European urheimat.

A direct child-parent relationship was detected in one burial, providing the oldest molecular genetic evidence of a nuclear family. Strontium isotope analyses point to different origins for males and children versus females. By this approach, we gain insight into a Late Stone Age society, which appears to have been exogamous and patrilocal, and in which genetic kinship seems to be a focal point of social organization.

Haak et al 2008 - Ancient DNA, Strontium isotopes, and osteological analyses shed light on social and kinship organization of the Later Stone Age. http://www.pnas.org/content/105/47/18226

Indeed, researchers of human prehistory have previously noted the relationship between the feasibility of the nuclear family as a competitive norm of social organization, and increased mobility owed to the invention of the wheel, attributed to the Proto-Indo-Europeans of the early 4th millennium BC.

Attachment: an excerpt from David Anthony's 2007 book The Horse, the Wheel and Language, p. 72.