Difficulty maintaining relationships is a major driver of modern singlehood, study suggests

People who report greater difficulties maintaining intimate relationships are more likely to be single, especially between relationships or voluntarily single, according to a new study published in Evolutionary Psychology.

A growing number of adults are living without intimate partners, prompting researchers to explore why singlehood is becoming increasingly common. While prior work has examined barriers to attracting a partner, less is known about the challenges people face after a relationship begins.

Menelaos Apostolou and colleagues addressed this gap by investigating whether difficulties in maintaining romantic relationships themselves might be a major contributor to remaining single. Their work builds on evolutionary perspectives suggesting that modern environments differ sharply from ancestral ones, creating mismatches that may hinder relationship functioning.

The authors note that in ancestral societies, relationships were often arranged or heavily constrained by social structures, meaning many skills needed for today’s freely chosen partnerships, such as conflict resolution, sustained investment, or emotional attunement, may not have been strongly selected for.

Modern independence, alternative sources of support, and strong protections for individual autonomy further reduce the incentives to stay in an unsatisfying relationship. These shifts may leave some people with relationship-maintenance challenges that contribute not just to breakups, but ultimately to different forms of singlehood.

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The study analyzed an existing dataset collected by Apostolou and Wang (2020), comprising 1,099 Greek-speaking adults recruited by four research assistants in Greece and Cyprus. Volunteers completed anonymous paper-and-pencil surveys placed in sealed envelopes. Participants ranged widely in age, with mean ages of approximately 32-33 for women and men, and included people who were married, partnered, parents, or single.

Participants completed a questionnaire containing 78 items designed to capture a wide range of difficulties people may have when trying to maintain an intimate relationship. These items covered challenges such as paying insufficient attention to a partner’s needs, sexual dissatisfaction, recurrent conflict, or becoming aggressive during disagreements.

Respondents indicated how strongly each difficulty applied to them on a five-point scale. The researchers then created a single overall score for each person by averaging their responses across all 78 items, which served as an indicator of how many obstacles they typically face in sustaining a romantic partnership.

Participants also described their relationship status in detail. Those who were single specified whether they were involuntarily single (wanting a relationship but struggling to attract partners), voluntarily single (not interested in being in a relationship at the moment), or between relationships (having recently ended a relationship and not yet formed a new one). Individuals who were in a relationship or married were grouped together for comparison against the singlehood categories.

Analyses revealed clear patterns linking higher levels of relationship-maintenance difficulty to greater odds of being single. For women, the association followed an inverted U-shape: as perceived difficulties increased from low to moderate levels, the likelihood of being between relationships, voluntarily single, or involuntarily single sharply increased. However, this effect reached a plateau or weakened at the highest difficulty levels.

For example, the probability of being between relationships peaked when women scored approximately 3.16 on the five-point scale. Similar patterns were observed for voluntary singlehood (peaking at 2.88) and involuntary singlehood (peaking at 2.83). This indicates that while relationship-maintenance challenges predict singlehood for women, those with moderate difficulties are often at the highest risk of being single, whereas further increases in difficulty have a diminishing impact on their relationship status.

For men, the association was strictly linear. Each one-unit increase in perceived difficulty was linked to a 2.36-fold increase in the likelihood of being between relationships and a roughly 1.8-fold increase in the likelihood of being voluntarily single. Unlike women, men showed no significant association between relationship-maintenance difficulties and involuntary singlehood, suggesting that for men, “maintenance” issues primarily lead to breakups or a choice to remain alone, rather than an inability to find a partner at all.

Overall, the findings suggest that for men, the greater the difficulty in maintaining relationships, the more consistently likely they are to be single, while for women the effect is strong but nonlinear.

This study relied on self-report data, which may introduce bias. As well, the cross-sectional design cannot establish causality. Further, Greek cultural context limits generalizability of findings.

This research highlights that maintaining intimate relationships, not just challenges in attracting partners, play a substantial role in who becomes and remains single, pointing to important psychological and societal factors that shape modern relationship patterns.

The research, “Difficulties in Keeping an Intimate Relationship and Singlehood,” was authored by Menelaos Apostolou and Timo Juhani Lajunen.