Monogamy Isn’t Linked to Better Sexual Health Than Non-Monogamy, Study Finds

Having more than one romantic or sexual partner does not inherently harm sexual health, according to a large new study published in the Journal of Social and Personal Relationships. The research found that people in non-monogamous relationships generally reported sexual wellbeing comparable to, or slightly better than, those in monogamous relationships.

The paper, titled Sexual Health in Monogamous and Non-Monogamous Relationships: Evidence From Convenience and Population-Based Samples, adds to a growing challenge to the idea that monogamy is inherently superior for sexual wellbeing.

The study distinguishes between consensual non-monogamy, including polyamory and open relationships, and infidelity, in which outside partners are kept secret. Across both arrangements, having multiple partners did not translate into worse sexual functioning, lower satisfaction or higher rates of sexually transmitted infections.

How the study was designed

The research team, led by Michelle Larva-Ruhala of the University of Turku in Finland, combined two complementary datasets. The first involved an online survey of 888 adults from countries including the United States, Portugal, Italy and Finland, comparing self-identified monogamous and consensually non-monogamous participants.

Participants described their relationship structure, whether encounters were considered infidelity and whether they kept sexual or emotional secrets from a primary partner. Validated questionnaires assessed sexual desire, arousal, lubrication, erection, ejaculation and satisfaction, with people who had multiple partners rating up to two partners separately.

The survey also asked whether respondents had ever been tested for or diagnosed with a sexually transmitted infection. This allowed researchers to compare self-care behaviors and health outcomes between monogamous and non-monogamous groups beyond simply counting sexual partners.

Key findings on sexual functioning

Overall, sexual functioning was broadly similar among monogamous and non-monogamous individuals. Women with multiple partners reported greater sexual desire, arousal and satisfaction with non-primary partners than with their primary partner, as well as higher scores than women who had only one partner.

The results echo earlier research suggesting that polyamorous people often experience greater eroticism with secondary partners and may diversify how their sexual needs are met. Among men, however, sexual functioning did not differ significantly by relationship type or between different partners.

Infidelity itself was generally not associated with worse sexual functioning. One notable exception emerged: men who kept emotional attachments and sexual encounters secret from a primary partner tended to report lower sexual satisfaction within that primary relationship, suggesting relational strain rather than direct sexual health effects.

Sexual health and STI outcomes

Polyamorous participants were 3.6 times more likely than monogamous individuals to have ever been tested for a sexually transmitted infection. Despite higher testing rates and having more partners, the prevalence of STI diagnoses did not differ between the two groups.

This pattern is consistent with earlier research suggesting that people in negotiated open relationships often maintain safer-sex practices at levels similar to or better than monogamous couples. By contrast, previous studies have suggested that people who cheat without disclosure are less likely to consistently use protection.

Larva-Ruhala said the researchers were surprised that infidelity did not show clear associations with poorer sexual health outcomes. The findings suggest that having multiple partners alone is not a reliable predictor of sexual risk and that behavior, communication and testing habits may matter more.

Evidence from a population sample

To reduce selection bias, a second study used a pooled, population-based dataset of 10,503 Finnish participants from genetic and behavioral research projects. Because these surveys were not specifically focused on non-monogamy, respondents were more likely to represent a broad cross-section of relationship experiences.

Participants reported their relationship structure and completed general measures of sexual wellbeing. For women, these included overall sexual desire and functioning. For men, researchers assessed premature ejaculation symptoms and how effectively they could control ejaculation.

The researchers also measured dyadic desire, meaning sexual interest toward an attractive partner. To make comparisons more balanced, non-monogamous and monogamous respondents were statistically matched on age, gender, sociosexual orientation, cohabitation status and partner gender.

Non-monogamy and desire patterns

In the population-based sample, non-monogamous men reported fewer early ejaculatory symptoms than monogamous men. Non-monogamous women reported higher overall sexual desire than women in monogamous relationships.

Across genders, people in non-monogamous relationships also reported slightly higher dyadic desire. When researchers separately examined participants who reported cheating or having non-consenting partners, infidelity still showed no clear negative effect on these measures of sexual health.

The findings are consistent with a broader body of research indicating that relationship and sexual satisfaction among people in consensually non-monogamous relationships are generally similar to levels reported by monogamous couples.

Limits, nuances and future research

The authors emphasize that the findings do not endorse infidelity or suggest that relationship agreements are unimportant. Instead, they indicate that people can maintain sexual health within both monogamous and non-monogamous relationship structures when risk and communication are managed effectively.

All measures relied on self-reports, which can be affected by memory errors and social desirability bias. The first study also grouped together some diverse forms of non-monogamy without fully accounting for differences such as cohabitation, hierarchy or specific relationship rules.

In the second study, the measure of infidelity combined current and past cheating, meaning that any negative effects on sexual health may have diminished over time for some couples. The authors argue that longitudinal research following partners as their agreements and behaviors evolve would provide a clearer picture.

Larva-Ruhala and her colleagues call for replication in other countries and cultures to determine whether the same patterns hold globally. As non-monogamous relationships become more visible, the researchers say discussions around policy, education and healthcare should be informed by evidence rather than assumptions about safety or satisfaction.

Article prepared by Victoria Caldwell.