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Polygamy vs Polyamory: Definitions + 3 Key Differences

Today’s article is all about polygamy vs polyamory, the definition of each one and the main differences.

Relationship goals. You hear those words, and you might have an idea of a couple who stays together through a lifetime.

While that’s the societal ideal, there are many other types of relationships that are considered to be just as satisfying, healthy, mature, and loving. 

When you hear that someone is in a “poly-” lifestyle, you might immediately understand that they’re talking about a relationship that involves more than two people. Stop there.

Observe your first thoughts. You might notice that you have preconceived notions of what this lifestyle means — or a prejudice against people who practice it. 

If you know anyone in the lifestyle or have participated yourself, you likely have a more nuanced understanding of the social dynamics.

Yet, for many people who’ve only ever been single or a part of a couple, the poly world can be commonly misunderstood and harshly judged. 

In fact, many people hear “polyamorous” but think “polygamist.” These lifestyles do have some overlap, but they also maintain key distinctions.  

Polygamy Definition

When you think of polygamy, do you automatically think of media versions like the HBO hit Big Love? Most of us do if we haven’t had direct experience with it.

You might even notice judgment about these relationships rising to the surface when you consider the media’s coverage of the types of polygamous relationships that involve minors, coercison, and questionable gender dynamics. 

Polygamy is defined as a man who has legally married multiple wives. Polyandry is defined as a woman who has legally married multiple husbands but is a much less common lifestyle comparatively.

Polygamy has roots in religious practices and is considered illegal in the United States. It is legal in other parts of the world and can be an accepted cultural and religious practice. 

Polyamory Definition

The etymology of the word “poly” comes from the Greek for “many” and “amor” translates to mean “love”.

This is why it’s applied to lifestyles that involve many lovers. As Dr. Heath Schechinger explains in a recent article, polyamory is defined as “the practice or orientation of having multiple sexual and/or romantic relationships simultaneously, with the full knowledge and consent of anyone involved.” 

Difference between polyamorous and open relationships

Polyamory is generally associated with open relationships, but not all polyamorous relationships are open. In an open relationship, people are free to form other sexual relationships outside the dynamic. In polyamorous relationships, people are free to form romantic and/or sexual relationships with other people. 

Polyamorous relationships can be open, allowing partners to freely date other people. Other polyamorous relationships are between multiple people with an agreement not to seek additional partners for relationships. It depends upon the polyamorous relationship in question and what all partners agree on for their dynamic.

Polygamy vs Polyamory: Main Differences

You might think that the only difference between polygamy vs polyamory is whether or not matrimony is involved — but you’d be mistaken.

There are several other key factors that separate these lifestyles from each other. You wouldn’t want to commit the faux pas of referring to polyamorous couple as polygamous. Here’s why.

Gender Equity

Polyamory has roots in feminism and is considered more equitable than polygamy. In polygamy, the husband is having intimate relationships with multiple wives.

Some polygamists may be open to the wives having intimate relationships with each other, but many are set up where only the husband has sexual encounters with the wives, which is why polamory is often considered to be more equitable for women.

In polyamory, everyone is given the same freedom to pursue other relationships with the idea that there is plenty of love to go around and that multiple relationships can meet different physical and emotional needs. It’s an equitable setup where everyone plays by the same rules, and there is no hierarchy in the arrangement.

Role of Religion

Another key difference between polyamory and polygamy is that polygamy has roots in religious practice. Religion is a key part of the relationship. It can also be a part of the culture. 

In the United States, polygamy is illegal and generally seen as less culturally acceptable than polyamory for multiple reasons.

One key reason is that polygamy usually involves a hierarchy where the husband is the head of household, and wives manage the household and children. The husband has multiple wives, but the wives don’t have the freedom to pursue outside relationships equal to that of the husband. 

While polyamorous people can be religious, the practice of polyamory isn’t rooted in religion. Anyone can participate, and there is no outside pressure from a religion dictating the rules of polyamorous relationships. 

While marriage is a big difference between the terms, not all polygamists attempt to make their relationships legal, particularly in the United States where it isn’t possible.

Instead, many polygamists see their relationship as being legal in the eyes of their church and community and treat each other as if they are husband and wives — whether or not the legal aspect exists.

Polyamorous individuals may or may not be married.

However, if they are married, they generally don’t look to secure other marriages. Instead, the marriage includes an open relationship that allows each partner to extend their interest outside of the bond. There are no vows taken. Instead, relationships are intentional and change as people do. 

Ethical Non-Monogamy

You may hear the term ethical non-monogamy (ENM) used interchangeably with polyamory, but polyamory is just one lifestyle under the ENM umbrella.

The idea behind ethical non-monogamy is that two people are choosing to have a non-monogamous relationship where either partner is free to have other romantic partners.

Anyone participating in ethical non-monogamy does so while understanding that honesty, consent, and communication are key factors to making these relationships ethical in nature.

The honesty doesn’t just extend to the current partner. It also extends to prospective ones. Disclosing the nature of their other relationship allows the potential partner to make an informed decision about whether they want to participate. This allows for full consent.

Although polygamy is illegal in the United States, it’s considered a form of ethical non-monogamy because everyone in the relationship is informed about the nature and rules of the relationship. 

There are many types of ethical non-monogamists, some who may refer to themselves as polyamorous. According to Dr. Jennifer Litner of Psych Central, the term ethical non-monogamy covers polygamy and polyamory as well as the following:

Open Relationships

In open relationships, all partners are free to have sexual partners outside the relationship.

Whether or not a romantic bond can be formed depends on the nature and agreement of the ethically non-monogamous individuals involved. 


Swinging is a concept you might be familiar with already. It’s when couples swap sexual partners. They may even attend clubs or parties with the specific intention to find other partners in this lifestyle.

Triads or Throuples

A triad or throuple involves groups of three people dating each other equally. It’s often mistaken for unicorn polyamory, or when a bisexual woman has sexual or romantic relationships with both members of the heterosexual couple — or heterosexual male and bisexual female in the couple.

The key difference between a triad/throuple and the unicorn dynamic is that the former is considered an equal dynamic and the latter has a hierarchy that prioritizes the couple. 


Polyfidelity is a concept where all partners in a group only have romantic or sexual relationships inside of the group. The relationships are open only within the established group of polyamorous individuals. 

Casual Sex 

If you are having casual sex, you might be surprised to learn that you are in an ethically non-monogamous lifestyle.

Partnering people for sex without the ties to a relationship falls under a polyamorous and ethically non-monogamous designation. 

Casual Dating

Someone who is not in a relationship but is dating multiple people is being ethically non-monogamous. By going on dates with different people, individuals are not being faithful or exclusive with one person and is free to explore other romantic and sexual possibilities. 

Society, Polygamy, Polyamory and Ethical Non-Monogamy

Because there’s a stigma attached to multiple relationships and ethical non-monogamy, many people within the lifestyle are private about their participation. While these lifestyles are growing in popularity, there’s not always a good understanding of them within pop culture. Instead, stereotypes abound.

If you know someone who identifies as polyamorous, don’t assume you understand their dynamic. Instead, here are two simple guidelines for interacting with someone in a lifestyle you’re not familiar with.

Mind Your Business

First of all, you’re not entitled to know someone else’s sexual or romantic dynamic. Unless someone has openly shared about their lifestyle, it’s actually not your business to ask.

At the end of the day, you don’t have to understand their choices to support them and be kind.

Be Curious, Not Judgmental

If they are open to sharing, listen with curiosity rather than judgment. Don’t assume you know what a particular lifestyle means to them. Ask — but be respectful in the way that you do. 

Polyamory and polygamy are often mistaken for each other, but there are significant differences between them. Understanding those differences can be key in communicating with someone who embraces one of these alternative lifestyles. 

As we grow to understand love and relationships, our understanding of what makes a healthy and happy one may change.

While society might be slow to embrace different lifestyles, it’s important to be informed — and, above all, to be kind, curious rather than judgmental, and to mind your own business. 

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Photo by Jessica Felicio on Unsplash

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