What Is Monogamy? Understanding Monogamous Relationships & Other Types

Describing what monogamy is can feel like trying to describe water to a fish. Because it's such a dominant approach to love and partnership and so ingrained into the very fabric of many societies today, monogamy may seem like simply the way relationships work.

Monogamy is the practice of forming romantic relationships with only one partner at a time, as opposed to having multiple partners at once. A monogamous relationship is a relationship where two people date and have sex with each other exclusively, and they don't share this type of connection with anyone else outside the couple. There is romantic, sexual, and emotional exclusivity between them.

Today, monogamy is the most mainstream approach to relationships across many societies, though it's by no means universal. Various cultures across the world practice polygamy (marriage between more than two people), and historically the majority of preindustrial societies engaged in polygamy of some sort, typically in the form of polygyny (two or more women sharing a husband). Monogamy is also a rarity among other mammals, with just 3% of mammals engaging in monogamy according to one recent analysis.

"Most of us have learned that monogamy is the 'normal' or even the 'traditional' relationship style and that nonmonogamy is an alternative, when, in fact, nonmonogamous relationships like polyandry, polygyny, [and] polygamy have been around for centuries," Jayda Shuavarnnasri, M.A., a sex and love educator who teaches about nonmonogamy and supports people exploring nonmonogamous relationships, tells mbg.

While there are many theories1 as to why human societies transitioned from primarily polygamous to primarily monogamous, what we do know is that monogamy as the social norm is a relatively recent development in the scope of human history.

The opposite of monogamy is nonmonogamy, which includes approaches like polygamy, polyamory, open relationships, and more. Consensual or ethical nonmonogamy has grown in popularity in recent years, with more than one in five people reporting they've been in a consensually nonmonogamous relationship2 before.

In consensually nonmonogamous relationships, a person may have more than one romantic or sexual partner at the same time. Critically, all partners are aware of these other partners and happily agree to the dynamic—meaning it's not "cheating" but rather an intentional part of the relationship.

Monogamy is not inherently better than nonmonogamy, nor is the opposite true, according to Shuavarnnasri. "Monogamy is great for some relationships and not for others."

Some people assume that nonmonogamous relationships are inherently less committed or less secure, but in fact, some research has found people in consensually nonmonogamous relationships actually tend to be more committed to their long-term relationships.

There's conflicting research on whether monogamy has had largely positive or negative effects on societies that practice it. Some common arguments about the benefits of monogamy include that it promotes gender equality (in comparison to polygamous societies, which have typically allowed men to marry multiple women but not the other way around) and that it creates a more stable environment for children. But many experts question these theories.

"Monogamous marriage has a pretty patriarchal history," Shuavarnnasri points out, adding for example: "When a girl is born into a family, she adopts her father's last name as a signal of the household that 'owns' her. The tradition of a father walking his daughter down the aisle is meant to symbolize the transfer of property to the soon-to-be-husband, which is further solidified by the bride adopting her husband's last name."

While that isn't to say that all marriages are patriarchal or that monogamous relationships are inherently oppressive toward women, Shuavarnnasri adds, it's important to note that monogamy has historically been an effective tool for systemically maintaining male dominance over women. Of course, many people today enter into monogamous relationships that are more egalitarian—but even so, the traditional division of labor in heterosexual relationships continues to have massive consequences for women's economic prospects.

Likewise, Shuavarnnasri argues that monogamy may not necessarily be the only or even the easiest context in which to raise a child.

"It's not a secret that raising a family requires a lot of work and money. With the rising cost of living, education, and housing, many millennials like myself are confronted with the reality that a dual-income household isn't enough to maintain a healthy family. This means that both parents have to work and make enough income to pay for day care since both parents spend most of their time working," they point out. "The interesting thing about nonmonogamous family dynamics is that children may have access to multiple 'parent figures' or trusted guardians that can care for them, and they do say 'It takes a village to raise a child.'"

The best way to start to answer this question is to examine what your desires are in relationships and where those desires come from, says Shuavarnnasri.

"We are social creatures, and most of our ideas are imprinted from the cultures, families, and relationships we grew up with," they note. "The tricky part about monogamy is that we live in a very heteronormative monogamous culture, where every love song and every movie sends the message that we all have one true love."

That means you'll need to really dig deep to understand your own authentic desires, separate from what might be expected from you by those around you.

If you're currently in a monogamous relationship and want to talk about the idea of monogamy or nonmonogamy with your partner, nonmonogamous relationship coach Effy Blue recommends starting slow.

"Start by suggesting a discussion around the concept of nonmonogamy rather than talking about opening up your current relationship and what that would look like practically," she writes at mbg. "Jumping straight into discussing your existing relationship structure can feel destabilizing or threatening, causing your partner to shut down or become defensive. Sharing an article you've read or a talk you've recently heard to kick off this discussion will eliminate potential tension around this topic."

Avoid evangelizing about the benefits of nonmonogamy, she adds—simply come with a balanced, thought-out perspective on the idea that's open for discussion. Talk about what you each think about monogamy as an approach to relationships as opposed to other, nonmonogamous approaches. It may also help to discuss how you each define what a relationship means to you in general.

Monogamy is a relationship structure between two people that is romantically and sexually exclusive; that is, they don't engage in this type of relationship with anyone else. In comparison, people in nonmonogamous relationships may have more than one romantic or sexual partner at a given time.