Bigamy vs. Polygamy

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There are different forms of marriage. In contrast to the common practice of only two partners marrying one another, societies exist whose members toe a different path. One such form is bigamy. Bigamy is defined as the act of going through a marriage ceremony with one person while legally married to another.

Polygamy is having more than one spouse at a time, so one must engage in bigamy to experience polygamy.

Read further to explore these two notable non-traditional systems of romantic partnership. you will find out there are additional similarities and differences between bigamy and polygamy. Other related practices will be examined as well.

What Is Bigamy?

Bigamy refers to a marriage between two people, where one-half of the couple is already in an existing marriage.

Bigamy can be intentional and consensual, with one spouse marrying a second spouse knowing that their initial marriage remains legally binding and with all parties consenting. It can also be intentional and not completely consensual, where two spouses may not be aware of each other.

It can also be unintentional, as the result of an attempted divorce that was never legally finalized. Bigamy is widely illegal, with all parts of the United States outlawing the practice.

People who are in bigamous unions are viewed as committing crimes. However, how that crime may be punished varies by state.

What Is Polygamy?

Polygamy is the general union of three or more people into marriage is known as polygamy. It is quite rare around the world, with less than 2% of the population engaged in this form of marriage.

For most people, this marriage is believed to be reserved for a man and multiple wives. This is, however, not always the case. Polygamy is a general description of a marriage carried out by any gender with multiple partners.

The three types of polygamy are polygyny, polyandry, and group marriage.

Polygyny

When a man marries multiple women at the same time, it is known as polygyny. This marriage is not a popular choice in most societies. This form of marriage has been noted throughout history in ancient Chinese, Hebrew, Hindu, and Arab cultures.

Although it is not common in the United States, with less than 0.5% of people practicing this form of marriage, the highest numbers are in Utah and Arizona. The West and Central part of Africa is known as the "polygamy belt" with some of the highest rates in Nigeria (28%), Mali (34%), and Burkina Faso (36%). It is also observed in certain parts of South America such as the Tsimane of Bolivia.

There are many reasons this form of marriage may be adopted.

  1. Girl Births Outnumber Boy Births: It may be observed in areas that have experienced a boost in the birth of girls. It would seem unfair to leave so many women single and without children.
  2. Men Die in War: Societies may have experienced war limiting the number of men available to women. Although not obligated or required, Muslim societies allow up to four wives, an option that was made available after a period of war. Polygyny is usually essential for the survival of these societies in certain circumstances.
  3. Religious Beliefs: Another reason for polygyny is rooted in religious beliefs. For example, the most well-known religious group that continues this practice is the Fundamentalist Church of Jesus Christ Latter-Day Saints (FLDS) which allows a man to take many wives. The men in this sect are taught that they need to have at least three wives to reach the highest level of heaven.

A man capable of partnering with multiple women is usually considered wealthy. This is because he must have the means to care for them all. If he is not able to take care of all of them equally, he is usually advised to not take more wives.

Forms of Polygyny

Here are the different types of polygyny:

  • Sororal Polygyny: The man takes sisters of a family as wives.
  • Nonsororal Polygyny: In this case, the man selects wives that have no relation to one another. 

What Is Polyandry?

Polyandry is a marriage practice where one woman has more than one husband at a time. Polyandry is observed in very limited communities. However, in societies where this is practiced, it is usually because there is a shortage of women to men. 

The Mosuo people in China are a matrilineal society known to practice matrilineal polyandry, where men and women are free to have multiple partners and to begin or end relationships as they please.

Forms of Polyandry

In a setting where a woman marries more than one man at a time, it is usually with either of two different sets of spouses:

  • Fraternal Partners: In this form of marriage, the union is usually between a woman and a set of sibling brothers. 
  • Nonfraternal Spouses: Here, women may instead marry a set of unrelated men for husbands. 

Women in Polygamous Unions Report Poorer Mental Health

While polygamous marriages may be viewed as unions of necessity in some areas, the women in this marriage usually report higher levels of dissatisfaction with life. These women also report more mental health issues in comparison to their monogamous counterparts.

Group Marriage

Group marriage is also a form of polygamy. This is an arrangement in which all parties involved engage in a marriage-like agreement. It may include more than one man and more than one woman.

Major Differences Between Bigamy and Polygamy

A union involving multiple partners may be a running theme in bigamy and polygamous unions. However, these relationships are not identical. To distinguish either union from the other, the following should be noted:

Level of Awareness for the Spouses

In typical fashion, spouses of polygamous unions are usually aware of the existence of the other partners. They typically all live together and have agreed to this form of marriage.

With bigamy, however, one or both parties are often oblivious to their partner's other marriage. In some cases, one spouse may be living a double life.

Different Classifications in the Law

In some countries, bigamy and polygamy are considered legal for men. Usually, a man marries his first wife, and additional marriage ceremonies occur with time. A marriage ceremony joining one person to multiple people at the same time is largely viewed as illegal.

Style of Living 

A bigamist will typically maintain two households to accomodate the separate partners. In contrast, polygamists may keep one household with all spouses present.

The Influence of Religion

Polygamy may be observed as the custom of a specific culture. In other instances, it may receive religious backing. Bigamy may appear temporarily on the journey in a polygamous marriage, but having two spouses in two separate households, does not typically receive cultural backing, nor is it recognized in religions.

Other Similar Marriage Arrangements

Like bigamy and polygamy, other setups exist that deviate from widely normalized monogamous relationships.

These include the following:

Group Marriages

A group marriage takes place where several males and several females are joined together as husbands and wives. This form of marriage is very rare, and may be observed for economic reasons supported by the partners. 

Open Marriage

In an open marriage, the partners agree to have sexual relationships with people outside of their union. These extramarital relationships are not considered cheating, as they are engaged in with mutual knowledge and consent.

Polyamorous Relationships

A polyamorous relationship recognizes that monogamy is only one of the ways romantic relationships may be forged. This relationship type accepts the possibility of loving more than one person at a given time. It is recognized as a non-possessive form of love, where all involved are aware that multiple partners exist in the union.

Polyamorous relationships come in many different forms, including but not limited to: hierarchical poly, anchor partners, triad, quad, polyfidelity, vee, kitchen table polyamory, solo polyamory, polycule, and more.

A Word From Verywell

In today's world, there are a variety of relationship patterns to choose from; however, when it comes to marriage, there are only a few countries where bigamy and polygamy are considered legal. These types of marriages have taken place throughout history, across cultures, and most often it was out of necessity.

In the United States, it is illegal to have more than one spouse, and is only practiced in the shadows by a few religious and cultural groups. Nevertheless, it is perfectly legal to have an open marriage if both spouses consent to one or both of them having other partners, and all parties must agree on the rules and boundaries.

7 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Elizabeth Plumptre

By Elizabeth Plumptre
Elizabeth is a freelance health and wellness writer. She helps brands craft factual, yet relatable content that resonates with diverse audiences.