The Disadvantages of Polygyny Make Couples Choose Monogamy


Written by Joseph Dunsay. After earning a Masters of Science in Ecology and Evolution, Joseph Dunsay became a science writer for international audiences.

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As we read about the challenges the first Jewish family faced in this part of the Torah cycle, we see how difficult polygamous relationships can be. Sarah had Abraham remove Hagar from the household. Rachael and Leah became rivals for Jacob’s attention. Even in a time and place that allowed polygamy, making all spouses in a marriage happy was monumental task.

The disadvantages associated with having multiple wives continue in modern times. They are responsible for the declining popularity of polygamy in Saudi Arabia according to an article on Yahoo. Saudis interviewed for the piece complained that it is impossible for a man with multiple wives to treat those wives equally. The rising cost of living motivates many Saudi men to seek monogamy, because they are unable to financially support the large number of offspring that result from traditional polygamous marriages. The growing popularity of monogamy in Saudi Arabia is an example of a behavior changing in response to environmental changes.

Animal behavior is the branch of biology that investigates how environmental, evolutionary, and physiological factors affect the behavior of all animals, including humans. Experts in animal behavior refer to actions related to reproduction and romance as mating behaviors. When partnering for reproduction, polygamous animals can practice polyandry, meaning each female partners with multiple males, or polygyny, meaning each male partners with multiple females. One male partnering with multiple females is the most common arrangement within the animal kingdom, because in most species, mothers invest much more in each offspring than fathers do.

This explanation for polygyny in other species fits well with the financial reason for the rise of monogamy in Saudi Arabia. Now that young Saudi men can expect to spend more on each child, they are shying away from the prospect of marrying multiple women. It also explains the patterns of polygyny seen in other countries.

A Beliefnet post about polygamy attributes the popularity of monogamy to financial constraints. Citing Israeli anthropologist Joseph Ginat, the website says that only a small percentage of men on the planet have multiple wives even though a third of humanity belongs to societies that permit polygyny. He said that only 10% to 25% of men in those societies practice polygyny and that most of those men tend to be in the upper class and have only two wives. His study of Israeli Bedouins indicated that polygyny was associated with being powerful and able to have many children.

Ginat explained Jewish and Israeli law regarding polygyny. Ashkanazi Jews, but not Sephardic Jews, took on a 1,000 year prohibition against polygyny starting in 987 C.E. in an attempt to reduce persecution from gentiles. Although the ban ended decades ago, modern Israeli law prohibits the creation of new polygamous marriages.

Glancing across regions and generations, one can see that humans are quite adaptable when it comes to marriage lifestyles. Jewish history includes the monogamy practiced by Isaac and Rebecca and the polygyny practiced by other ancestors. In this generation, different cultures have different norms that can change in response to changing environments. It is quite likely that marriage norms will continue to evolve as conditions keep changing.

After earning a Masters of Science in Ecology and Evolution, Joseph Dunsay became a science writer for international audiences. His LGBT erotic e-book launched in the summer of 2015.