107: Is Monogamy (Un)Natural?

Sep 20, 2022

Often, when people who have been in monogamous relationships for their entire adult lives find themselves in infidelity situations, they start asking questions about monogamy like, “Is monogamy natural or unnatural?” This seems on the surface like a good question to ask yourself, but there’s a little more to it.

There is so much messaging about monogamy being natural, and therefore what is expected of you. Of course, there is a counterargument that monogamy is unnatural and it’s a construct that has been forced upon society. A lot of people are told that monogamy is the only natural way to live, only to find themselves wanting to try something new. This is why asking the right questions about monogamy really does matter.

Tune in this week because Dr. Marie Murphy is unpacking the question, “Is monogamy natural or unnatural?” Marie is diving deep into what natural even means, the meaning that gets applied to the word natural, and why it only gets more complicated when you try to bring the natural versus unnatural debate to how you think about your relationships, monogamy, and what you really want in your sexual and romantic life.

If you’re ready to take this topic deeper in a confidential and compassionate environment, you can schedule an introductory coaching session with me by clicking here!

What You’ll Learn from this Episode:

  • How biologically determining what’s “natural” isn’t as simple as you might think.

  • The societal messaging we receive around what is “natural” and expected of us as humans.

  • Some of the things we do as humans that are considered “unnatural” that we don’t think twice about.

  • Why what counts as monogamy, exclusivity, or cheating varies from person to person.

  • The most important questions for you to consider when deciding whether or not you want to be monogamous or not.

  • Why monogamy doesn’t need to be monotony, and your relationship doesn’t need to be monogamous.

  • How to decide, with or without your partner, what you want your relationship to look like.

Listen to the Full Episode:


Featured on the Show:

Hi everyone, I’m Dr. Marie Murphy. I’m a relationship coach and I help people who are engaging in anything they think counts as infidelity to deal with their feelings, clarify what they want, and make decisions about what they’re going to do.  There’s a lot of advice out there about infidelity that is little more than thinly veiled judgment, but I believe you are entitled to guidance and support that respects the fullness of your humanity and the complexity of your situation, no matter what you’re doing.  And that’s exactly what I provide!  So if you’re ready to sort out your infidelity situation in a way that’s right for you, let’s work together.  You can schedule an introductory coaching session with me through my website, mariemurphyphd.com. I can’t wait to meet you.

Today we’re going to talk about monogamy.

Sometimes, when people who have been in monogamous – or ostensibly monogamous – relationships for their entire lives find themselves in infidelity situations, they start asking a lot of questions about monogamy.  And I think this can be a very valuable thing to do, for many reasons which will become clear throughout the course of this episode, BUT I think there are useful and not-so-useful questions to ask about monogamy.  Or helpful and not-so-helpful questions you can ask yourself about your relationship with monogamy.

And I’m just going to come right out and say point blank that one of the questions that people ask about monogamy a lot that I don’t think is particularly HELPFUL to consider is, “Is monogamy natural?”  Or “is it unnatural?”  Either way you phrase it, the problem is the same.

But before I tell you what with the problem with that question is, let me say this.  I completely understand WHY people ask these kinds of questions!  And I’m completely sympathetic to these sorts of questions even if I don’t think they’re the most useful ones to consider.  Here’s why: there are a lot of messages out there that tell us that some sorts of behavior are natural, and some are unnatural.  And the implication is usually that natural = good, and unnatural = bad.  And therefore, many of us are pretty concerned with whether our behavior or our desires count as natural or unnatural, because we want to be good, and we don’t want to be bad.  To put it in simple terms that might be overly simplistic, at times.  

And of course, a lot of people out there would try to tell you that monogamy is natural, and therefore expected of you.  There is also a counter-argument to that, namely, that monogamy is NOT natural, and that we’re all naturally non-monogamous, and monogamy is something that has been forced upon us.  

But the argument that monogamy is natural, and other forms of relationships are unnatural is a little more dominant these days.  And what’s important for us to recognize is that many people have been told, very explicitly, for their entire lives that the only normal, or natural, way to live out one’s sexual and romantic life is to find a mate, meaning, ONE mate, and stay with them and only them for the rest of their lives.  Depending on where and when you grew up, and who you grew up around, you may have gotten this message loud and clear.  You may STILL be getting this messaging loud and clear.  

And what happens a lot is, people hear these kinds of messages, then they try this out, and they try to live this way.  They partner up, which can mean a lot of different things, but for a lot of people, it means getting married, and doing so at a fairly young age.  And however earnestly people may enter this sort of relationship, they sometimes find that they don’t really like the whole marriage thing, or perhaps they fall in love with someone other than that mate they’re supposed to stay with for life, or they have sex with someone or someones other than the only person they’re supposed to be having sex with, and they’re like, wait, what’s going on here?  How come nobody told me that I could be attracted to more than one person at once?  How come nobody told me that I could desire someone other than the only person I’m supposed to desire?  What’s going on?  And sometimes, what people wonder is what’s going on with THEM, and whether their experience is normal or not.  And when people start to wonder whether they’re normal or not, they sometimes want really clear standards against which they might measure themselves.  And this is where some people really want to know, once and for all, whether or not monogamy is natural or unnatural because they think that this designation will help them make sense of their own experiences, AND hopefully reassure them that there’s nothing wrong with them.

And I’m totally sympathetic to all of that.  I’m totally sympathetic to wanting to make sense of your experience of life, and be able to put your experiences into some sort of context that resonates with you.  And, in a world that is obsessed with dualistic categories of good or bad, right or wrong, normal or abnormal, natural or unnatural, so many of us desperately want to find some sort of assurance that we fall into the “good” categories.

And yet, I still want to suggest that the question of whether monogamy is natural or unnatural is not a helpful one, and I will now tell you why.

First and foremost, what in the Sam hell counts as “natural”?  We could have a month-long discussion about what we mean by “natural,” and what makes something natural or not.  But I won’t subject you to that.  For the sake of brevity, let me just point out that often designations of what counts as “natural” or “unnatural” are far from neutral, and are based upon assumptions that we might want to challenge, and may be part of an ideological agenda that we don’t want to buy into.

Sometimes, what people mean when they ask if monogamy is natural or unnatural is whether or not it is biologically determined.  There is a long history of biological determinism within the study of human sexuality, and human romantic relationships, and human family life.  For a lot of reasons, people have found it very appealing to attempt to attribute aspects of human social behavior to particular aspects of our biology.  But many explanations of human behavior that attempted to attribute the various ways people live out their sexual and romantic lives to a particular biological source were never scientifically sound, and have been criticized and even completely discredited. 

Non-biological determinists argue that our biological forms, that is, our human bodies and all of their intricate components, may give us the CAPACITY to live out our sexual and romantic lives, starting with giving us our sheer physical existence, but biology does not determine the manner in which we do so. 

For instance, when it comes to sex, our bodies, which are definitely biological organisms, give us the capacity to move around and engage in the kinds of physical activities that people think of as sex.  We do different things with different body parts, and our nervous system gives us the capacity to experience particular sensations.  And there’s definitely biology involved in that.  But our biology does not determine how we like to have sex, or what bodily behaviors we think count as sex, or who we like to have sex with, or how often, or at what time of day, or whatever.  Yes, people have tried to argue that biology actually DOES determine all of those things, but if you care to examine the scholarly literature on these topics, I think you will find that these arguments do not hold water.    

It may be helpful to consider that although our bodies have the capacity for hunger, and a biological need to eat food, biology does not determine what we like to eat, or find appealing to eat.  What counts as food at all, and what counts as delicious food, is socially determined, and varies widely across time and place.  The biological need to fuel our bodies does not determine the flavors we put together in our cuisines.

Okay, there’s a lot more I could say about biological determinism and why it’s problematic, but I’m not going to subject you to a lengthy sociological diatribe here.  Instead, I’ll just point out that humans do a LOT of things these days that are not biologically determined, and arguably, are not “natural” in any possible sense of the term.  For example, we fly on airplanes.  Is there anything within our biology that dictates we do that?  To the best of my knowledge, there is not.  And moreover, do our physical bodies like the experience of flying on airplanes?  Did our biology dictate the invention of airplanes?  As a social scientist, my answer to all of these questions is no.  But that doesn’t mean that we should or shouldn’t fly on planes.  It’s just an example of why the question of whether something is natural or not isn’t necessarily helpful.  Flying on planes has become a routine part of human life at this point.  Whether you want to do it or not may be a question worth asking, but invoking “nature” or “naturalness” into the debate may get you anywhere.

Similarly, humans manufacture and consume products like Diet Coke, and Cheetos.  I think I talked about the first and only time I ate a Twinkie in a recent episode.  That shit ain’t natural!  I don’t care what definition of “natural” we are using here – no matter how you cut the cake, Cheetos and Diet Coke and Twinkies are not natural.  And yet these products sold in stores all over the place as food items.  And even if some people have deemed these sorts of products unhealthy, plenty of people eat them.  All the time!   

Furthermore, many humans spend hours staring at screens every day.  We artificially heat and cool our homes.  We buy and wear clothing that is made of synthetic fibers, some of which are, by some people’s estimations, toxic for us to come into any contact with, much less regular, sustained contact with.  

So the point here is that we do a lot of things that could quite easily be considered completely unnatural and we don’t go around asking ourselves whether we should worry about that or not.  

Monogamy is a social arrangement that was developed under particular socio-historical circumstances, through human interactions and negotiations.  Like many aspects of our lives, social dynamics, rather biological imperatives, are the source of these arrangements.  So in a sense, it might be fair to say that monogamy is unnatural, insofar as it is not dictated by nature as the only way to live, or the only way to live out one’s romantic life or sexual life.  But this is true of ANY way we choose to configure our romantic and sexual lives.  

ANY way of configuring our sexual and romantic lives is a human invention.  That’s true whether it’s monogamy or something else.  Although some people might want to argue otherwise, nature, or biology, does not dictate that we live out our romantic or sexual lives in ANY particular way.  People love to make the argument that the human species would die out if people did not live out their romantic or sexual or familial lives in a particular way, but those arguments have been dismantled over and over again.  It may be true that there are particular ways in which human reproduction can be accomplished, but these days, you don’t even need vaginal-penile intercourse to occur to make a baby.  There are plenty of other ways we can get the necessary genetic material together in the right place at the right time in order to keep making new humans, if need be.

So in broad terms, the question isn’t whether monogamy is natural or not, the question is, what happens when monogamy is as dominant of a social arrangement as it is in this day and age and place?


One of the biggest problems with monogamy is that it’s more or less imposed on so many of us.  Although in a sense we all have the option to opt out of monogamy, that’s not an option that is offered to many of us in a very explicit way.  It’s not like when we’re little, someone sits us down and says, “Okay kid, as you grow up, you will probably want to engage in sexual and romantic relationships at some point in your life, and there are all kinds of options for what that could look like for you.  You could choose to get married and have a committed monogamous relationship.  Or you could choose from a whole bunch of other options, such as this or this or that.”  No!  What happens, for a lot of us, is that there’s explicit or implicit pressure to get married.  This may apply less to you as if you identify as something other than heterosexual from an early age, but it may not.  The norm of marriage isn’t only offered to or imposed upon straight people, for better or worse.

Now this doesn’t mean that monogamy is bad, or marriage is bad.  Some people like monogamy quite a lot.  Some people like marriage quite a lot.  And some people decide that even though there are some things that they don’t love about monogamy or marriage, they prefer those sorts of arrangements to other ways of arranging their romantic lives.  Let me insert a very important side-note here: I am not saying that monogamy and marriage are necessarily synonymous!  You can be married, and not be monogamous, and you can be monogamous and not be married.  I apologize for any conceptual slippage, or the appearance of any conceptual slippage.  But whether or not monogamy and marriage go together in practice or not, the point is that some people like these ways of organizing their romantic and sexual lives just fine.  However, I want to suggest that the extent to which monogamy is thrust upon us as the most legitimate – or perhaps the ONLY legitimate – way of living out one’s sexual and romantic life does not collectively do us many favors.  So many people enter ostensibly monogamous relationships without having had the opportunity to consider alternatives.  Even if in a sense we’re freely choosing monogamous relationships, it’s not all that much of a choice if we don’t know that other options exist.

That said, as anyone who practices any form of ethical non-monogamy will tell you, there are drawbacks - as well as benefits - to non-monogamous relationships arrangements, too.  It’s not exactly that monogamy is this big bad oppressive social structure that is imposed on us, and if some other way of doing relationships were dominant, we’d all be much better off.  If monogamy was not as socially expected or prescribed as it currently is, and another sort of relationship configuration were as dominant as monogamy currently is, I guarantee that people would grumble about that, too.

So for practical purposes, the important question for a lot of people to consider for themselves is NOT “is monogamy natural?” but “do I want to do monogamy or not?”

Now, some of you may be saying, “Well, I understand that it doesn’t matter whether monogamy is natural or unnatural, but my entire family, and everyone else I know, believes that monogamy is natural and anything else is unnatural, so therefore, even I didn’t want to be in a monogamous relationship, I kind of have to be.  I want to suggest two things.  You may have a challenge on your hands in terms of dealing with other people’s opinions, but the fact that other people in your life have opinions does not mean that you have to be in a monogamous relationship.  Or do anything else, for that matter.  So often we think we have to solve for other people’s opinions, but we don’t.  Our opportunity lies in solving what we make other people’s opinions mean for us.

The second thing I want to suggest is that we sometimes use other people’s opinions to distract ourselves from the task of deciding what WE actually like or want.  With monogamy, your job is not to focus on whether other people like it or don’t.  It can be easy to get hung up on that!  But your job is to keep your focus on what YOU like or dislike about monogamy.

If you’re disliking monogamy, what do you dislike?  Why do you dislike it?  And what would you like instead, in terms of the setup of your romantic life?  What sort of arrangement would you prefer?  These are really important questions to allow yourself to consider.

It’s also important to be aware that there’s no one way to do monogamy, or to have a monogamous relationship, AND important to be aware that people’s definitions of monogamy vary a LOT.  On top of that, people often enter relationships with the assumption or understanding that they’re going to be monogamous, without really discussing what monogamy means to them, to each member of the couple.

And in a way, I think this is completely understandable.  To talk about what monogamy means to us, or to talk about what we’re okay with or not okay with at the outset of a relationship may seem incredibly unromantic.  We might not want to even consider the possibility that our partner might ever even have a sexual or romantic THOUGHT about anyone other than us, much less have a discussion about what counts as monogamy and what counts as cheating.  Many people have really romanticized and latched onto the idea of exclusivity, and if you’ve been thinking this way, it may feel very threatening to talk about the parameters of monogamy or commitment in your relationship, because the implication that there’s any alternative to our partner being completely devoted to us may seem terrifying.  

And in addition to possibly not having the wherewithal to talk about how we want to define monogamy with a new partner, we may never have really individually thought all that much about what we want monogamy to look like for us.  We may have made certain assumptions about what monogamy means or entails, but we may have never really sat down and given it all that much thought.  And as such, people often effectively sign up for monogamy without really knowing what they’re signing up for.

And this can lead to some really interesting tensions within relationships.  For example, sometimes people who are in heterosexual relationships discover, after having gotten pretty invested in their partner, that their partner does not want them to have any friends of the other sex.  Sometimes women don’t want their men partners to have friends who are women, or vice versa.  Some people think that monogamy means that you, as their partner, are the other person of the other sex that you get to hang out with.  Not everyone conceptualizes monogamy like this, but some people sure do.  

And of course, other people conceptualize monogamy in completely different ways!  For some people, monogamy means you don’t have sex with someone else, and that’s where the boundary lies.  That gets complicated too, because people have different ideas of what “sex” means or includes.  Some people think that the only thing that counts as sex is contact between a penis and a vagina.  This is obviously a very heteronormative frame of reference, but it’s one that many people operate from.  And, beyond that, some people think that penile-vaginal intercourse only counts as sex if the penis ejaculates.  Isn’t that interesting?  Now, obviously, not EVERYONE thinks this way, even if they identify as heterosexual.  Some people think that kissing counts as sex.  And of course, not everyone identifies as heterosexual, and not everyone thinks of sex as activity that involves vaginas and penises. 

Short tangent here.  When I used to teach undergraduate sociology of sexuality classes, on the first day of class, I would give the students the assignment to go home and ask someone what sex is.  If they asked for clarification, I’d tell them to ask someone they know how they define sex, or what sex means.  And students would look at me like I was either crazy or joking or both when I would give them this assignment.  And then they’d come back to the next class meeting, and say, “People have a really hard time defining what sex is!”  Or, “The person I talked to thought sex meant something really different than what I thought it meant!”  And that of course was the whole point of the homework assignment.  The point was for them to consider the possibility that maybe other people’s definitions of sex might be different from theirs, AND to encounter the possibility that we may think we know what sex means or entails or includes, but when push comes to shove, if you will, these understandings may be fuzzier than we thought they were.  

So the point for you is that it’s important to recognize that people tend to have assumptions about what sex means or entails or includes, and those assumptions may be different from yours.  And this may matter for your experience of monogamy.  If you think that having a sexual thought about someone other than your partner is tantamount to having sex with them, your experience of monogamy is going to be very different that it would be if you and your partner were to sit down and explicitly decide that there are certain things you will do and not do with other people, and you’ll only do with each other.

That brings me to the very important point that you and your partner CAN decide, together, what you want monogamy to look like for you, if you want to.  As I said earlier, there’s no one way to do monogamy.  Dr. Tammy Nelson, who was a guest on this podcast last year I think, talks about how couples can create monogamy agreements that work for them.  Effectively, the couple gets to decide what “counts” as monogamy for them as a couple.  And some people who think they don’t like monogamy find it very liberating to create a monogamy agreement with their partner, so that everyone can get clear on their own expectations and give their partner the opportunity to agree to participate in the relationship under the desired terms.  Sometimes the problem isn’t monogamy, it’s what you think monogamy has to mean.  

Now, let me make it clear that I’m not trying to sell monogamy, or pitch monogamy.  That is not my agenda at all; I do not have a pony in that race.

But the point is that sometimes when people tell me that monogamy isn’t natural, what they’re really saying is that they don’t like it.  And more specifically, they’re saying they don’t like a particular version of it.  And although you have every right to decide you don’t want to do monogamy, you may want to examine how you’re defining it and executing it before you decide whether you need to make a few tweaks in the system, or throw the system out entirely.  And a lot of people don’t take the steps of figuring out what monogamy means to them, and then coming to any kind of an agreement about what they want their monogamous relationship to look like with their partner.  And then they’re like, “I don’t think monogamy’s right for me,” and I’m like, “Hold up… let’s get clear on what you think monogamy is before we go any further.” 

I want to reiterate the point that I made earlier that any way we choose to live out our romantic lives is a human construction, or a social construction.  There’s nothing in our biology that dictates that we even need to experience the what we consider to be “romance.”  There’s nothing in our biology that makes it more natural for us to couple up with one person, or be involved with more than one person at the same time.  Humans have the biologically-enabled CAPACITY to do all sorts of things.  Our biology gives us our big sophisticated brains, which give us the capacity for thinking and creating meaning out of our lives.  But existence of our human brains has not determined the particular thoughts humans have entertained over time, and our brains, in and of themselves, have not created our shared ideas about what romantic configurations are possible or ideal or acceptable.  Biology may give us the capacity to think, but it doesn’t determine what we think.

Similarly, our biology gives us the capacity to desire more than one person at a time, and care about more than one person at a time, and have sex with more than one person at a time and get involved with more than one person at a time.  But our biology also gives us the capacity to choose what we want to do with these options.  We have minds that are capable of thinking desirous thoughts about more than one person at a time, and bodies that are capable of feeling attracted to more than one person at a time.  And our minds also have the capacity to decide what we want to do with these capacities.  Do we want to organize our lives so that we can explore more than one relationship at a time in an above-board way?  Do we prefer the potential benefits and drawbacks of monogamy to the potential benefits and drawbacks of any other way of organizing our sexual and romantic lives?  Thinking about whether monogamy is natural or not will not be particularly useful if you’re trying to answer these questions.  

Now, given that I mostly work with people who are cheating, part of the problem folks are experiencing is often that they’re already in a relationship that’s supposed to be monogamous, but they’re not behaving monogamously, and they’re unsure about a lot of things.  They aren’t sure if the problem is monogamy, or their existing committed relationship, or the fact that they’re so thrown off by whatever infidelity they’re engaging in that they just don’t know what they think about anything anymore.  And that’s totally normal, but we can’t eat the whole elephant all at once.  We have to work through our situations one step at a time.  So if you ARE at a moment in your life when you’re wondering where you stand in regards to monogamy, in addition to wondering about a bunch of other things too, I encourage you to take some time to think ONLY about monogamy.

Here are some of the questions you may want to consider:

First of all, how do you define monogamy?  What does monogamy mean you do and don’t do?  


What don’t you like about monogamy, and why don’t you like it?

Is there anything you do like about monogamy?  What do you like about it and why do you like it?

What are the terms and conditions of monogamy in your relationship?  Have you defined them explicitly within your relationship?  Meaning, have you ever had a conversation about monogamy with your partner, or the person you’re supposed to be in a monogamous relationship with?

If you were going to change your relationship setup in some way, what would you change?  For example, would you want to make your definitions of monogamy more explicit with your partner, and perhaps change the standards you’ve been operating from?  Or would you want to do away with monogamy altogether?  If you did that, what would your ideal non-monogamous life look like?  What do you imagine the benefits and drawbacks of this new arrangement would be for you?

These may be great questions to ask yourself even if you aren’t in the midst of an infidelity situation, but if you are engaging in anything you think counts as infidelity, this may be a really good time to get as clear as you can about what you want your sexual and romantic life to look like going forward.  So give this stuff some thought.

And of course, if you find yourself getting LOST in your own thoughts, let me help you use your mind in a way that’s actually USEFUL.  Our minds make wonderful servants, but terrible masters, so if you’ve been thinking and thinking and thinking about your infidelity situation but you still don’t know what you want, or what you want to do, let’s work together.  You can schedule an introductory coaching session with me through my website, mariemurphyphd.com.

All right everyone!  Thanks for listening.  Have a great week!  Bye for now. 


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