If you look at the animal kingdom, there is an observable pattern to recognize some animals are polygynous, the male having multiple mates, and some that are polyandrous, the female has multiple mates. Note this pattern: When the female is larger like in bees, ants, and humpback whales, then the female has multiple mates. When the male is larger, as in chickens, lions, to lionfish, males mate with multiple females.
If you create a monogamous pairing of chickens with only one rooster and one hen, then the rooster will mount the hen too frequently, causing stress to the hen, often creating a bald spot of plucked back feathers, and it will reduce her egg production. For chickens, the rooster to hen ratio is generally best at one to five or one to ten. With human males being about 15% larger than human females, you would biologically expect humans to be slightly polygamous, and when monogamous, for females to be stressed with too much sex, or males to be frustrated with too little.
Many people see Christianity as the primary source of strict monogamy in world history. However, this is due to a lack of knowledge of history, and a lack of defense of polygamy, as a taboo too dangerous to consider.
It was the Greek reformer Solon who instituted strict marital monogamy in Greek culture in 600 B.C. While economists (David D. Friedman, Price Theory, Ch. 21) can show that polygamy by itself benefits females assuming they have a choice in the matter to benefit from increased choice. But there is no evidence that Solon created strict monogamy to reduce women’s choices, instead it was for the opposite side, to reduce competition among men. In order to facilitate the change, several cultural conditions were created or solidified, such as state sponsored prostitution, support for homosexuality, as well as a common belief that romantic love was only between men.
By the time of Christ, pagan Greek culture had practiced centuries of strict marital monogamy, as well as did the pagan Roman culture they influenced. The first six Roman emperors had 25 wives between them, but all by serial monogamy of divorcing one to marry the next. So even the Roman emperors were bound by the power of their pagan cultural taboos.
So what of Jews under the rule of Greeks and then Romans? I’ll let George Joyce provide the answer in his “Christian Marriage: An Historical and Doctrinal Study” (1933):
“When the Christian Church came into being, polygamy was still practiced by the Jews. It is true that we find no references to it in the New Testament; and from this some have inferred that it must have fallen into disuse, and that at the time of our Lord the Jewish people had become monogamous. But the conclusion appears to be unwarranted. Josephus in two places speaks of polygamy as a recognized institution: and Justin Martyr makes it a matter of reproach to Trypho that the Jewish teachers permitted a man to have several wives. Indeed when in 212 A.D. the lex Antoniana de civitate gave the rights of Roman Citizenship to great numbers of Jews, it was found necessary to tolerate polygamy among them, even when though it was against Roman law for a citizen to have more than one wife. In 285 A.D. a constitution of Diocletian and Maximian interdicted polygamy to all subjects of the empire without exception. But with the Jews, at least, the enactment failed of its effect; and in 393 A.D. a special law was issued by Theodosius to compel the Jews to relinquish this national custom. Even so they were not induced to conform.”
Here we see the interesting case that pagan Rome restricted and persecuted polygamy and the Jews for practicing it, including Diocletian, an equally infamous persecutor of Christians. And then this pattern even continued with the Christian emperor Theodosius. After this period, Christian Roman Emperors would continue the pagan Roman pattern of increasing the punishment for polygamy so that Emperor Justinian outlawed polygamy to the degree that only a few of the wealthiest Jews were able to avoid coerced divorce and keep their wives.by paying a fine of ten pounds of gold in 535 A.D. By the ninth century, polygamy brought the death penalty. In order to end over eight centuries of persecution, Judaism in Europe under Rabbi Gershom decided to self-monitor among European Judaism and prohibit it among their own in the 11th Century.
This is similar to what happened to Mormons in America. The persecution of them became so great they would become the first religion to claim to receive a message from God suspending polygamy. They likewise began rigorous self-policing and persecution of their own fundamentalist sub-sects who refused to give up polygamy.
But this does not address the New Testament for Christians, and how Christians came to generally oppose polygamy. Many centrally influential Christian writers admitted that the New Testament did not prohibit polygamy, including Augustine, Thomas Aquinas, and Martin Luther, who wrote:
“I confess that I cannot forbid a person to marry several wives, for it does not contradict the Scripture. If a man wishes to marry more than one wife he should be asked whether he is satisfied in his conscience that he may do so in accordance with the word of God. In such a case the civil authority has nothing to do in the matter.” De Wette II, 459, ibid., pp. 329–330.
But still others made and still make a claim that it is prohibited by a few different Biblical arguments. First is a claim already disproven by the history above, that polygamy was already not practiced by Jews of the first century, and so didn’t require specific opposition. Next is an argument based on the parallels in Paul’s phrase, “Let each man have his own wife and each woman her own husband.” However, the English of this phrase hides a detail from the Greek that proves and defends polygamy was assumed and allowed.The phrase uses two different words for “own”: heautou and idios. The difference is to clarify that a husband has a wife exclusively that he cannot share. The wife has a husband using a collective “own”, such as in the phrase “Each man return to his own city”. In this case, the man does not exclusively own the city in opposition to others as co-owners, just as a wife’s ownership of her husband does not prohibit other wives owning him as husband.
The final argument is the phrase used for a qualification for elders, “husband of one wife” in most English translations. However, the Greek is mias gunaikos andra. The word mias can mean either “one” or “first”. Context should decide, but in church history, a cultural bias colored the interpretation from the beginning. Gentile converts to Christianity, coming from Greco-Roman opposition to polygamy would assume it mean “one”. But Jewish converts to Christianity would assume this is requiring a man who would keep and not divorce his first wife. Indeed, even though John Calvin opposed polygamy, he acknowledged that the early Jewish Christians continued in polygamy.
Whether one accepts the Jewish or pagan Greek method of interpretation depends on if one contemplates Jesus statement, “Until heaven and earth pass away, not the smallest letter or stroke shall pass from the Law.” In other words, the Old Testament’s concepts and definitions of marriage are used with Jesus correcting misinterpretation. Jesus is not creating replacement definitions.. In contrast to this is the gnostic approach which tries to argue that the Law was evil and materialistic, as was God in the Old Testament, and Jesus was trying to oppose the Old Testament God. In this, official Gentile Christianity orthodoxy, at least through Imperial decrees and laws, chose, perhaps partly by accident, partly by excessive anti-Jewish bias, to follow the gnostic approach to argue against polygamy, even if it was generally critical of gnosticism.
Another issue is an attempt to reinterpret Old Testament texts claiming support for monogamy, such as Adam having only one wife, or Abraham’s second wife causing conflict. But yet, if these did not imply a strict monogamy then, then they can’t be correctly interpreted later to do so. Take the example of Abraham, the example of faith, lived with at least a third wife and unnamed concubines without any implied wrongness.
Further, God used a metaphor of Himself as a polygamist with two wives in Ezekiel 23. To claim that God would use the example of something unethical as an attribute of Himself is dangerously close to blasphemy.
Given that I argue for the legitimacy of polygamy, the question arises, how do you stop the abuse of it? The New Testament did not have to provide an answer as the Old Testament, along with the Jewish understanding of marriage was sufficient. In Exodus 21:10 a man cannot take an additional wife unless he can do so without diminishing his financial support of his existing wife, or her sexual needs. Even a very wealthy man can only satiate a limited number of women unless they all enter the marriage with low sex needs. Further, a wife with sexual desire greater than her husband effectively prohibits him from ever taking a second wife. This limitation makes each additional wife beyond one gets exponentially more difficult. This in effect provides a give and take balancing that reduces the problem of the excessively mounted and stressed hen, or the under-satiated rooster.