Recent research published in journals evolution and human behavior suggest that how individuals perceive their own attractiveness and desirability compared to their romantic partners is related to relationship strain. This finding indicates that regardless of whether the relationship is monogamous or open, feeling more substitutable than the primary partner tends to predict greater feelings of conflict and competition. However, people who are in consensual, non-monogamous relationships, practice open communication, and experience joy in their partner’s other romantic relationships tend to report less jealousy and conflict overall.
In relationship psychology, mate value refers to a person’s overall desirability as a romantic partner. This concept includes characteristics such as appearance, personality, social status, and access to resources. When partners evaluate each other, they often notice differences in these characteristics, which is known as spousal value discrepancy.
Past research has shown that people often feel anxious when they perceive their mate value to be lower than that of their partner. They may worry that they will be replaced by someone more attractive and successful. This anxiety tends to lead to jealousy and behaviors aimed at protecting one’s partner from rivals, something psychologists call mate retention.
Most previous research on this topic focused only on monogamous relationships. Monogamy theoretically reduces competition because people expect only one partner at a time. Consensual non-monogamous relationships work very differently because partners explicitly agree that they can have romantic or sexual relationships with other people.
People in consensual non-monogamous relationships may regularly observe differences in mate values because they are openly exposed to their partners’ other partners. Faith Swanson, a researcher at Texas State University’s Department of Psychology and a prevention expert at the Senicor Foundation, wanted to investigate how these dynamics play out in different mating styles. The study was supervised by Rhonda N. Balzarini, assistant professor of psychology at Texas State University and affiliated researcher at the Kinsey Institute.
“What’s always fascinated me is that humans have a long history of flexible mating systems, but a lot of relationship research still focuses almost entirely on monogamy,” Swanson says. “We wanted to know whether the same evolutionary processes that shape jealousy, conflict, and mate protection in monogamous couples also apply to consensual non-monogamous (CNM) relationships, or do people adapt to those relationships differently?”
The researchers analyzed data from a final sample of 512 participants. This group included 312 people in monogamous relationships and 200 people in consensual non-monogamous relationships. Participants were recruited through social media advertisements and online forums. Although the sample was international, spanning 62 countries, the majority of participants were Caucasian women living in Europe or North America, with an average age of approximately 35 years.
Participants completed an online survey about themselves and up to two current romantic partners. They answered questions to rate their own mate value and each partner’s mate value. To do this, they rated how difficult it would be to replace themselves or their partner in various areas such as physical attractiveness, mental stability, and financial resources.
The study also measured the frequency of conflict with each partner. Participants reported their anticipated jealousy by rating how distressed they would feel if their partner became intimate with someone else. To measure spousal retention, participants indicated how often they used specific tactics to retain their partner. Psychologists typically divide these into two categories. One is the “benefits-giving” tactic, which is positive behavior such as giving gifts or showing love and care, and the other is the “cost-imposing” tactic, which is negative behavior such as monopolizing a partner’s time or belittling a competitor.
Another measure assessed intrasexual competitiveness, the tendency to view people of the same sex as romantic rivals. Finally, participants in consensual non-monogamous relationships answered questions regarding their specific relationship maintenance strategies. These strategies include revealing attraction to others, openly discussing jealousy, establishing a hierarchy of partners, and experiencing empathy. Empathy is defined as feeling pleasure or positive emotions when your partner has a romantic or sexual relationship with someone else. The survey also asked about structural practices, such as how partners allocate resources such as time and money, their willingness to help their partners raise their children, and their commitment to sexual health and safer sex.
The analysis revealed some subtle patterns in how partners compare to each other. “In both monogamous and CNM relationships, people who perceived their mate value as low were more likely to report having more conflict with potential rivals and being more competitive,” Swanson explained.
“From an evolutionary perspective, it makes sense,” Swanson added. “If someone feels like they are more of a replacement than their partner, they may be more sensitive to potential threats to the relationship, as losing a valued ancestral partner may have had important effects on reproduction and survival.”
Some of the results challenged previous assumptions about key partnerships. “One finding that surprised us was that spousal value discrepancy did not consistently predict jealousy or mate retention in primary relationships, even though previous research suggested it should,” Swanson said. “Instead, the strongest and most consistent associations involved conflict and intrasexual competition.”
The data provide evidence of a different pattern when focusing on secondary partners in non-monogamous relationships. A secondary partner typically refers to someone who is less involved with the individual or in a new relationship compared to the primary partner.
“We were also intrigued to find that in CNM relationships, perceiving one’s own mate value as higher than that of a secondary partner was associated with greater conflict, jealousy, and mate retention,” Swanson told PsyPost. “This suggests that relationship dynamics may differ depending on whether someone is interacting with a primary or secondary partner, raising interesting questions for future research.”
Researchers suspect this may occur because secondary relationships are often newer, less stable, and lack the established boundaries of primary pair bonds. Without a deep history of conflict resolution, perceptions of differences in desirability can cause frustration, especially if the highly desirable person feels entitled to a particular quality of the relationship or fears a precarious arrangement will fall apart.
Engaging in specific communication strategies was associated with reduced relationship tension. “At the same time, one of the encouraging findings was that the dynamics of mate value are not fixed,” Swanson said. “For example, in CNM relationships, the practice of openly communicating about jealousy and discussing attractiveness in others led to less conflict and jealousy.”
“This suggests that while emotional processes such as jealousy and competitiveness may have deep evolutionary roots that influence how we perceive the safety of relationships, how we manage and integrate them is flexible and shaped by processes such as communication, trust, and negotiation between partners,” she explained.
On the other hand, endorsing a partner hierarchy that explicitly prioritized one partner over another was associated with more frequent conflict, increased jealousy, and increased rates of mate-protection. Scientists also found that individuals with high mate value who have multiple partners may engage in more active mate retention techniques, such as gift-giving with benefits and displays of affection, to maintain relationships.
The scientists also noted some differences between men and women that may reflect differences in evolutionary mating strategies. For example, men who perceive their own mate value as low are more likely to view other men as romantic competitors because they feel an increased need to compete for access to a partner. In contrast, women in monogamous relationships reported increased competitiveness when they perceived their partner as highly attractive. Researchers suggest that because women are often oriented toward long-term mating, they may be fiercely protective of highly desirable partners to protect established bonds. Both men and women in non-monogamous relationships reported less sexual and possessive jealousy compared to men in monogamous relationships.
Readers should note that psychological factors do not exist in isolation. “Most of the effects were relatively mild, which is common in psychological research because human relationships are incredibly complex,” Swanson noted. “Spouse values explained part of the picture, but certainly not the whole story.”
“I think mate value is one of many cues people use to assess the security of a relationship,” Swanson added. “Factors such as communication, attachment style, trust, personality, and shared experiences are also very important. Our findings suggest that perceptions of value toward a spouse contribute to relationship dynamics, but they are only one piece of a much larger puzzle.”
To avoid misunderstandings, the researchers emphasize the limitations of their data. “An important takeaway from this study is that participants’ perceptions of their own mate value were more strongly associated with conflict and intrasexual competition than perceptions of their partner’s mate value or disagreement between the two partners,” Swanson emphasized. “In other words, how someone perceives their own worth explains more about conflict and competitiveness than how they perceive their partner.”
Because the study design is cross-sectional, only one snapshot can be taken in time. “It is also important not to interpret these findings as causal,” she cautioned. “Because the study is cross-sectional, we cannot conclude that spouses’ values lead to conflict or competition.”
“It is equally possible that experiences of conflict and competition influence how people evaluate themselves and their partners, so future longitudinal studies will be needed to disentangle these relationships,” Swanson said.
The sample size for analyzing secondary partners was also relatively small. Only 88 participants provided data to a second partner. This small sample limits the statistical power for certain results. This means that results related to secondary partners need to be replicated in larger groups.
“I’m looking forward to continuing to explore how evolved mating psychology interacts with modern relationship structures,” Swanson said of her future plans. “Humans have a very flexible mating system, but I think there’s a lot we don’t understand about how evolved psychological mechanisms affect relationships.”
“In the future, we would like to conduct longitudinal studies and collect data from both members of the couple, rather than relying on one partner’s perspective,” she added. This approach captures the reciprocal dynamics that exist between both people in the couple.
“I think one of the most important contributions of this study is that it expands relationship science beyond a monogamy-only perspective,” Swanson concluded. “Rather than assuming that the same psychological processes operate in the same way in all relationships, our findings suggest that while some mechanisms are shared, others depend on the relationship context and how partners manage challenges together.”
“Ultimately, this study confirms that relationships, whether monogamous or consensual non-monogamous, are shaped not only by perceptions of mate value, but also by the communication and maintenance practices that partners use to navigate the relationship,” she said.
The study, “How spousal value discrepancies are associated with jealousy, mate protection, intrasexual competition, and partner conflict in monogamous and consensual non-monogamous relationships,” was authored by Faith L. Swanson, Rhonda N. Balzarini, Justin K. Mogilski, and Taylor M. Himes.
