Why emphasise on monogamy?

[Angrboda]

When polygamous marriages occur in premodern societies, they are overwhelmingly likely to involve polygyny (one husband, multiple wives) as opposed to polyandry (one wife, multiple husbands). Overall, of the 1,231 cultures in the Ethnographic Atlas Codebook, 84.6 percent are classified as polygynous, 15.1 percent as monogamous, and 0.3 percent as polyandrous. Polygyny is much more common than polyandry because evolutionarily, the benefits of polygyny for men are much higher than the benefits of polyandry for women.

Are People "Naturally" Polygamous?

Monogamy's spread in the West had something to do with the influence of Christianity, but not as much as you might expect. Mainstream Christianity has always endorsed and enforced monogamy, and as Christianity spread across Europe in the centuries following the fall of Rome, monogamy spread along with it. However, Christianity's condemnation of polygyny has never been as straightforward as anti-polygyny church leaders would have preferred, because no Biblical passages explicitly prohibit plural marriage. Indeed, leaders of breakaway Christian polygynous sects, like 16th-century German Anabaptists and 19th-century American Mormons, have always been eager to point out that several central Old Testament figures are polygynists. Abraham, for instance, had two wives simultaneously, and Solomon had 700 (plus 300 concubines).

Why We Think Monogamy Is Normal