For decades, monogamy has been treated as the benchmark for a healthy relationship, with consensual non-monogamy cast as a risky departure from it. Two recent studies put that assumption to the test.
The first, a meta-analysis led by researchers at La Trobe University in Melbourne, pooled data from almost 25,000 people. It found no evidence that monogamous people are more satisfied with their relationships or their sex lives. The second, a large international study, identified the everyday practices people in non-monogamous relationships use to keep those relationships healthy. Read together, they suggest that how partners make and keep their agreements may matter more than the structure of the relationship itself.
What is consensual non-monogamy?
Consensual non-monogamy, often shortened to CNM, describes relationships in which partners agree that one or more of them can have other romantic or sexual connections. It covers a range of arrangements, including polyamory, open relationships, swinging and “monogamish” relationships, where a couple who largely see themselves as monogamous agree to particular sexual exceptions.
Consent is what separates CNM from infidelity. Everyone involved knows about the arrangement and has agreed to it, although the details vary from one relationship to the next.
The La Trobe team uses the term “monogamy-superiority myth” for the belief that exclusive relationships are inherently happier and more stable. In their view, it shapes how people in non-monogamous relationships are seen, including by clinicians and policymakers.
Testing the monogamy-superiority myth
The meta-analysis, published in The Journal of Sex Research, searched six academic databases for studies published up to 2024. The team also asked experts in the field for unpublished data. The final analysis included 35 studies covering 24,489 participants, most of them from North America and Australia. Every study measured relationship or sexual satisfaction and grouped participants as monogamous or consensually non-monogamous.
People in monogamous and non-monogamous relationships reported essentially the same levels of relationship satisfaction, and the same held for sexual satisfaction. The pattern appeared in heterosexual and LGBTQ+ samples alike. The researchers also found no sign that the result reflected a bias towards publishing particular findings.
Where the data allowed a closer look at specific arrangements, a few small differences emerged. People in monogamish relationships reported slightly higher relationship satisfaction than monogamous people. Polyamorous people and swingers reported slightly higher sexual satisfaction. The lead author, Associate Professor Joel Anderson, has stressed that the study does not show non-monogamy is better, only that monogamy carries no built-in advantage.
What helps non-monogamous relationships work
A second study, published in the Archives of Sexual Behavior, asked a practical question: what do people in successful non-monogamous relationships do? Its lead author, Justin Mogilski of the University of South Carolina Salkehatchie, came to the topic expecting non-monogamy to bring more conflict and less satisfaction. He set out to understand how some people seemed to avoid those problems.
The international research team first asked 429 people with CNM experience to nominate the most and least effective ways of handling challenges such as jealousy and shared finances. From their answers, the team built the Multiple Relationships Maintenance Scale. They then tested it with 4,290 participants across several countries and languages. The final scale measures nine practices:
Disclosing attractions to other people
Regulating jealousy
Experiencing compersion, the joy some people feel when a partner enjoys another relationship
Sharing sexual experiences that involve other people
Maintaining sexual health
Setting a hierarchy between partners
Distributing material resources such as money thoughtfully
Being willing to share childcare
Managing reputation, including keeping some relationships private
In general, people who used these practices more often reported higher relationship quality. This held for monogamous people as well as non-monogamous ones. Regulating jealousy and sharing sexual experiences were linked to higher relationship quality on almost every measure the team used.
The study also measured infidelity, meaning contact with others that a person deliberately kept secret from a partner. People who reported more infidelity used the maintenance practices less and reported lower relationship quality. The lead author reads this as evidence that deception and broken agreements, rather than multiple partners as such, are what damage relationships.
Partner hierarchy, a contested idea in polyamorous communities, was linked to better relationship quality, against some expectations. Compersion, often held up as an ideal, showed only a weak connection.
What the research means for therapy
People in non-monogamous relationships do not always receive good care. A 2018 study of 249 people in CNM relationships in the United States and Canada examined their experiences of therapy. According to the lead author’s summary, 41 per cent of their therapists assumed they were monogamous. About one in ten clients ended therapy early after a negative experience related to their relationship structure.
These studies give no reason to treat relationship structure as the problem in itself. The work usually lies in the agreements partners make and how honestly they keep them. In practice, affirming therapy for non-monogamous relationships can include:
Treating jealousy as a feeling to understand and work with, rather than proof that non-monogamy has failed.
Helping partners make their agreements explicit, including how resources are shared and how sexual health is managed.
Distinguishing a freely negotiated arrangement from secrecy or pressure, since consent sits at the heart of CNM.
Supporting couples who are considering opening their relationship to explore their reasons and expectations, without steering them towards or away from it.
Several of the practices in the second study were associated with stronger relationships in monogamous couples too. Talking openly about attractions to other people, for example, was linked to more trust and greater investment in the relationship.
Polyamory and non-monogamy counselling in Australia
At Progressive Therapeutic Counselling, we offer online counselling across Australia for people in non-monogamous relationships of every kind, with specialist experience in sexuality, kink, gender and relationship diversity. Whether you are exploring non-monogamy for the first time or have practised it for years, we bring knowledge of relationship diversity so you do not have to explain your relationship from scratch. To talk about counselling, get in touch with PTC.
About the research
Both studies have limits. Most of the evidence in the meta-analysis came from volunteers in Western countries, and people unhappy in non-monogamous relationships may have been less likely to take part. Both studies capture relationships at a single point in time, so they cannot show cause and effect. The authors of the second study caution that adopting the practices they identified will not necessarily improve a relationship, and they note that parts of their scale need further refinement.
Anderson, J. R., Hinton, J. D. X., Bondarchuk-McLaughlin, A., Rosa, S., Tan, K. J., & Moor, L. (2025). Countering the monogamy-superiority myth: A meta-analysis of the differences in relationship satisfaction and sexual satisfaction as a function of relationship orientation. The Journal of Sex Research. This article is open access.
Mogilski, J. K., Miller, G. F., Jonason, P. K., et al. (2026). How do people maintain consensual non-monogamy? An international development and validation of the Multiple Relationships Maintenance Scale. Archives of Sexual Behavior. This article is open access.
Schechinger, H. A., Sakaluk, J. K., & Moors, A. C. (2018). Harmful and helpful therapy practices with consensually non-monogamous clients: Toward an inclusive framework. Journal of Consulting and Clinical Psychology, 86(11), 879–891.