In cultures that permit men to take multiple wives, the intra-sexual competition that occurs causes greater levels of crime, violence, poverty and gender inequality than in societies that institutionalize and practice monogamous marriage.

That is a key finding of a new University of British Columbia-led study that explores the global rise of monogamous marriage as a dominant cultural institution. The study suggests that institutionalized monogamous marriage is rapidly replacing polygamy because it has lower levels of inherent social problems.

"Our goal was to understand why monogamous marriage has become standard in most developed nations in recent centuries, when most recorded cultures have practiced polygyny," says UBC Prof. Joseph Henrich, a cultural anthropologist, referring to the form of polygamy that permits multiple wives, which continues to be practiced in some parts of Africa, Asia, the Middle East and North America.

"The emergence of monogamous marriage is also puzzling for some as the very people who most benefit from polygyny -- wealthy, powerful men -- were best positioned to reject it," says Henrich, lead author of the study that was recently published in the journal Philosophical Transactions of the Royal Society. "Our findings suggest that that institutionalized monogamous marriage provides greater net benefits for society at large by reducing social problems that are inherent in polygynous societies."

Considered the most comprehensive study of polygamy and the institution of marriage, the study finds significantly higher levels rape, kidnapping, murder, assault, robbery and fraud in polygynous cultures. According to Henrich and his research team, which included Profs. Robert Boyd (UCLA) and Peter Richerson (UC Davis), these crimes are caused primarily by pools of unmarried men, which result when other men take multiple wives.

"The scarcity of marriageable women in polygamous cultures increases competition among men for the remaining unmarried women," says Henrich, adding that polygamy was outlawed in 1963 in Nepal, 1955 in India (partially), 1953 in China and 1880 in Japan. The greater competition increases the likelihood men in polygamous communities will resort to criminal behavior to gain resources and women, he says.

According to Henrich, monogamy's main cultural evolutionary advantage over polygyny is the more egalitarian distribution of women, which reduces male competition and social problems. By shifting male efforts from seeking wives to paternal investment, institutionalized monogamy increases long-term planning, economic productivity, savings and child investment, the study finds. Monogamy's institutionalization has been assisted by its incorporation by religions, such as Christianity.

Monogamous marriage also results in significant improvements in child welfare, including lower rates of child neglect, abuse, accidental death, homicide and intra-household conflict, the study finds. These benefits result from greater levels of parental investment, smaller households and increased direct "blood relatedness" in monogamous family households, says Henrich, who served as an expert witness for British Columbia's Supreme Court case involving the polygamous community of Bountiful, B.C.

Monogamous marriage has largely preceded democracy and voting rights for women in the nations where it has been institutionalized, says Henrich, the Canadian Research Chair in Culture, Cognition and Evolution in UBC's Depts. of Psychology and Economics. By decreasing competition for younger and younger brides, monogamous marriage increases the age of first marriage for females, decreases the spousal age gap and elevates female influence in household decisions which decreases total fertility and increases gender equality.
Monogamy Reduces Major Social Problems of Polygamist Cultures
University of British Columbia, ScienceDaily, January 24, 2012

More men than women in Muslim countries: List of countries by sex ratio (Permanent link)

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Another Muslim Perspective Scrutinized

In Islam, why can a man can get married to two, three or four women, while a woman cannot get married to more than one man?

First: Polygamy was not innovated by Islam. It was known in Judaism and other religions. Many of the Prophets (peace be upon them) were polygamous, such as Abraham and Sulayman, as mentioned in the Torah.

Argumentum Ad hominem "tu quoque" logical fallacy


Second: With respect to polygamy, women cannot be compared with men, since comparison implies similarity with regard to the matter in question, which is not the case here. There are major differences between men and women: · Women have menstrual cycles for quite a long period of their lives, while men do not.

Yes, 12 weeks out of the year is such a looooooong time. Especially when those weeks are spread out over the entire course of a year. How can men handle the wait? Also, it is a known biological fact that women who live together will have synchronous menstrual cycles - meaning that the man will still have that week every month where he can't have sex, because all of his wives will be menstruating.


· Fertility for men usually lasts longer than it does for women. Normally, women stop being fertile before 50, while most men continue to be fertile for a while longer.

And that means old men should continue having children although they might die the next day of old age and be unable to support their families any longer?


· Women go through pregnancy, delivery, and post-natal bleeding while men do not.

And for all the woman's hard work and suffering, her husband should be allowed to sleep with other women because he can't handle the post-natal six-week wait.


· Men can sire children several times in one year with multiple partners while women cannot do so. No matter how many partners she has, she can only carry the child of one at a time.

So, populating the earth with as many children as possible is more important than the happiness of the wife and the health of the marriage.


Women have more affection than men and in most cases cannot behave unemotionally. The strong and concentrated affection women have does not allow them to cope in a relationship with many men and at the same time. Her nature prevents her from satisfying two men at one time.

This statement is illogical and also scientifically inaccurate.


If two men should approach one woman, it would cause cause confusion in genealogical relations.

Not anymore thanks to DNA testing! Paternal testing in the United States costs a few hundred dollars. This is also only relevant if you are obsessed with paternity.


Men are the ones commanded in Islam to protect and maintain women. They are obligated to spend on the family while women are not.

In other words, since the Quran commands that women be dependent on men, then men should be allowed to have multiple sex partners because they are obligated to maintain women.


For one woman to have more than one husband, there are many disadvantages. It is practically impossible for it to work.

Two paychecks is a disadvantage? Two men to mow the lawn is a disadvantage?


But more than one woman for one man is lawful in Islam for the following reasons: 1. Polygamy preserves the stability of families, for example if the first wife is barren or afflicted by some illness, polygamy will offer her a chance that can save her from divorce or living alone.

Since adoption is clearly not an option, and a woman's breeding abilities are more important than anything else.


2. The nature of a man makes polygamy something of dire necessity, for their sexual desires can often not be fulfilled by one woman who goes through menses, pregnancy, post-natal bleeding, and sickness, all of which are barriers to sex, or due to the frequent need of men to travel. Polygamy is far better than adultery which is widespread in the West. Polygamy is also better than divorce.

Allah is responsible for the nature of man...and he made men incapable of monogamy? This argument clearly insults men.


3. Polygamy benefits women. The second wife accepts it for her benefit to save her from staying alone; taking into account that she was not forced into it.

Well guess what? A Muslim man does not need the agreement of his first wife to take a second wife.


4. It is the best solution to save women from being lonely. Women live longer than men, they are more numerous than men, and in many cases men are facing danger and death more than women.

This statement is so completely illogical and ridiculous that we're simply going to move on to the next one...


5. Islam has set conditions and controls that secure the woman’s rights. A man cannot have more than four wives. He has to treat all of his wives justly in living expenses, the time he spends with them, and in all matters under his power. Anyone incapable of being just will not be allowed to engage in polygamy. Allah says: “But if ye fear that ye shall not be able to deal justly (with them) then only one.”

They forgot this quote: [Quran 4:129] Ye will not be able to deal equally between (your) wives, however much ye wish (to do so). But turn not altogether away (from one), leaving her as in suspense. If ye do good and keep from evil, lo! Allah is ever Forgiving, Merciful. Allah said that men will not be able to deal equally with multiple wives...but he still didn't ban polygamy.


We as Muslims believe that what Allah has made lawful is full of wisdom and justice and has been prescribed for the benefit of all mankind, whether we know the reasons for it or not. We should keep in mind that Allah did not even make it obligatory for us to marry in the first place. He encourages people to get married and allows polygamy for people who are capable of being just.

In other words, if you can't understand it...shut your brain off. This Muslim's argument is more offensive to men than it is to women.

Return to "Polygamy in Islam" page.