The character of Wonder Woman has been challenging traditional roles since her creation in the 1940s. Following the recent box office success of the movie Wonder Woman—which earned a total of $103 million dollars in its opening weekend—an origin movie was released about Wonder Women and her creator William Marston. As it turns out, Martson also challenged relationship norms in the context of his own life. Based on a true story, Professor Marston and the Wonder Women shines light onto what appears to have been a successful, loving relationship between himself, his wife Elizabeth, and their lover, Olive. The public’s reaction has been mixed. Individuals who have been successfully living in non-monogamous relationships are hoping that their day of validation has arrived. But what does the research say about how non-monogamous relationships stack up against traditional, monogamous relationships?

Monogamous relationships generally continue to be held as the gold standard for relationship success.1 For example, people have been shown to expect those in monogamous relationships to have higher relationship quality, lower , and higher trust and satisfaction compared to non-monogamous relationships.2 However, newer empirical work examining non-monogamous relationships has begun to challenge these assumptions.1,3 Building on this work, Séguin and colleagues recently conducted a new, high-powered study comparing three types of relationships:4 relationships, (intimate, loving relationships where individuals have more than one partner, with the knowledge and consent of all partners) open relationships (a marriage or committed relationship in which the partners agree that each may engage in extramarital sexual relationships, without this being regarded as ) and . The study compared the quality of relationships that fit each of these three categories.

In this study, participants in all three kinds of relationships completed a survey that measured sexual satisfaction, relationship satisfaction, closeness, trust and commitment. They also answered questions about how fair (equitable) they believed their relationship to be, (e. ., “Considering what you put into your relationship, compared to what you get out of it, how does your relationship ‘stack up’”?) The participants were instructed to answer these questions with their partner (or with non-monogamous individuals, their primary partner) in mind.

Out of the 3463 participants, 79.6% were in traditional monogamous relationships (N = 2758) and 13.5% were in an open relationship (N = 468), with 6.8% classifying themselves as polyamorous (N = 237). On average, all three groups of participants reported relationships that were highly committed, trusting, equitable, and emotionally and sexually satisfying. There were no significant differences by relationship type. The findings provide some evidence that monogamous relationships do not tend to be higher-quality than non-monogamous relationships.

This study had some limitations, such as not allowing polyamorous individuals to identify as polyamorous if they were currently only involved with one partner, and asking the polyamorous individuals to rate only their primary partner, therefore not capturing the relationship quality with their additional partners. It is also not clear from the way the findings are presented whether the results hold both with and without control variables. However, the results are consistent with a growing body of literature suggesting that non-monogamous relationships tend to be just as satisfying as monogamous relationships.

Further research is still needed on factors that may contribute to relationship quality among non-monogamous couples. The present study examined whether relationship quality indicators differed overall between three types of relationship agreements, and found them to be equally satisfying. A clear next step for researchers would be to examine how and why these non-monogamous relationships are thriving, even compared to more traditional relationships. We are also in need of longitudinal studies—studies that survey couples at multiple time points—to better understand how these relationships change over time.

Overall, although researchers have only just begun to study non-monogamous relationships scientifically, the results that have been published so far are exciting and thought-provoking. For researchers who study , this work challenges our current thinking about many aspects of relationships, such as jealousy (is it really unavoidable?), (can we really only become attached to one partner at a time?), and commitment (does commitment really require us to “forsake all others”?). For the public, these findings may go a long way toward helping to destigmatize individuals in polyamorous and other kinds of open relationships.

This post was coauthored by Annelise Murphy at the University of Utah.

We are currently conducting a study looking at people’s experiences with opening up their relationships. If you are thinking about opening up your own relationship in the near future, we invite you to participate in our study!