Polygamy is rare throughout most of the world. In the U.S., having spouselike relationships with more than one person under the same roof was criminalized in 1882. Today, people in the U.S. are rarely prosecuted for living with multiple romantic partners, but every state has laws against getting married while already being married to someone else.

In February, Utah passed a bill to reduce the penalties for adults who voluntarily live in polygamous relationships, making the practice an infraction, a low-level offense that is not punishable with jail time.

In other parts of the world, including swaths of the Middle East and Asia, polygamy is legal but not practiced widely. And in some countries – particularly in a segment of West and Central Africa known as the polygamy belt – the practice is frequently legal and widespread.

A Pew Research Center report about living arrangements in 130 countries and territories published in 2019 analyzed the number of people residing in polygamous households, as well as other types of households. Here are some key findings from that report, and from a separate study of customs and laws around the world.

Data on the prevalence of polygamous households was part of a Pew Research Center report on household composition by religion around the world. Not all people who practice polygamy live in polygamous households. Sometimes two or more wives of the same man each have their own homes. See the methodology for details on household type categories. Details on polygamy laws around the world can be found through the OECD Development Centre and the United Nations Human Rights office.

Only about 2% of the global population lives in polygamous households, and in the vast majority of countries, that share is under 0.5%. Polygamy is banned throughout much of the world, and the United Nations Human Rights Committee, which has said that “polygamy violates the dignity of women,” called for it to “be definitely abolished wherever it continues to exist.” But there often are limits to government administration of marriages. In many countries, marriages are governed by religious or customary law, which means that oversight is in the hands of clerics or community leaders.

Living in polygamous households is very uncommon in most places
In some African countries, sizable minorities of people live in polygamous households

Polygamy is most often found in sub-Saharan Africa, where 11% of the population lives in arrangements that include more than one spouse. Polygamy is widespread in a cluster of countries in West and Central Africa, including Burkina Faso, (36%), Mali (34%) and Nigeria (28%). In these countries, polygamy is legal, at least to some extent. Muslims in Africa are more likely than Christians to live in this type of arrangement (25% vs. 3%), but in some countries, the practice also is widespread among adherents of folk religions and people who do not identify with a religion. For example, in Burkina Faso, 45% of people who practice folk religions, 40% of Muslims and 24% of Christians live in polygamous households. Chad is the only country in this analysis where Christians (21%) are more likely than Muslims (10%) to live in this type of arrangement.

Many of the countries that permit polygamy have Muslim majorities, and the practice is rare in many of them. Fewer than 1% of Muslim men live with more than one spouse in Afghanistan, Pakistan, Bangladesh, Iran and Egypt – all countries where the practice is legal at least for Muslims. Polygamy is also legal in Saudi Arabia, Qatar, the United Arab Emirates and other neighboring countries, but these were not included in the study due to data limitations. Muslim supporters of polygamy often cite Quran verse 4:3, which instructs men to take as many wives as they can take care of, up to four, and they also point out that the Prophet Muhammad had multiple wives. Historians have noted that Islamic guidance on polygamy was issued amid wars in Arabia in the seventh century, when there were many widows and orphans requiring financial support, and that polygamy created a system for them to be cared for. To this day, polygamy is most common in places where people, and particularly men, tend to die young.

The Jewish Torah and Christian Old Testament refer to several instances of accepted plural marriages, including by Abraham, Jacob and David. However, the practice was disavowed by these groups in the Middle Ages, and polygamy generally has not been condoned by Jews or Christians in recent centuries. Still, polygamy sometimes was practiced by certain Christian sects, including by members of the Church of Jesus Christ of Latter-day Saints (sometimes called Mormons) in the U.S. until the late 1800s. Some Mormon splinter groups still practice polygamy.

Religion often plays a role in how polygamy is governed and practiced within a single country. In Nigeria, for example, polygamous marriage is not allowed at the federal level, but the prohibition only applies to civil marriages. Twelve northern, Muslim-majority states do recognize these unions as Islamic or customary marriages. In India, Muslim men are allowed to marry multiple women, while men of other groups are not. However, in countries where polygamy is common, it often is practiced by people of all faiths. That’s the case in Gambia, Niger, Mali, Chad and Burkina Faso, where at least one-in-ten people in every religious group measured live in households that include husbands with more than one spouse.

Is polygamy moral?

Polygamy usually takes the form of polygyny – when a man marries multiple women. Polyandry, which refers to wives having more than one husband, is even rarer than polygamy and mostly documented among small and relatively isolated communities around the world. While polygamy laws are usually skewed in favor of allowing men – but not women – to take multiple spouses, many countries’ laws also speak to the rights of women.  In Burkina Faso, for example, where polygamy is common, spouses must agree that a marriage will be polygamous at its outset for the husband to be allowed to take another wife in the future. In Djibouti, a judge records the existing wives’ opinions on any new marriages and investigates the husband’s socioeconomic situation before approving a marriage contract with an additional wife.

One-in-five U.S. adults believe that polygamy is morally acceptable, a recent Gallup poll found. This share has almost tripled (from 7%) since the question was first asked in 2003, but is still among the least accepted behaviors Gallup asks about. Self-described liberals are much more likely than conservatives to see polygamy as morally acceptable (34% vs. 9%).  A Pew Research Center survey published in 2013 found that Muslims around the world are divided about polygamy: While majorities in several sub-Saharan African countries and pluralities in parts of the Middle East describe polygamy as morally acceptable, Muslims living in Central Asia as well as Southern and Eastern Europe tend to say that polygamy is immoral.

Stephanie Kramer  is a senior researcher focusing on religion at Pew Research Center.