Scientists uncover surprising factor behind how people choose partners

New research suggests that the social world people grow up in can shape their dating preferences as strongly as biological sex. The study, published in Evolution and Human Behavior, finds that socioeconomic status significantly influences how individuals see themselves as partners and what they seek in relationships.

The findings challenge long-standing assumptions in evolutionary psychology that men and women are largely driven by fixed, sex-based instincts. Instead, the data indicate that human mating strategies respond flexibly to local conditions, resource access, and social competition.

Rethinking Classic Dating Theories

Traditional evolutionary theories propose that men prioritize physical attractiveness and women prioritize resources and security. These ideas have often been treated as universal, with relatively little attention to how inequality and social context might reshape preferences.

Lead author Anthonieta Looman Mafra, a postdoctoral fellow at the University of São Paulo, set out to test how strongly context matters. She drew on strategic pluralism theory, which argues that people adopt different mating strategies depending on environmental pressures, risks, and opportunities.

Mafra also wanted to correct a common bias in psychological research, which often relies on university students from relatively privileged backgrounds. In a highly unequal country like Brazil, she reasoned, romantic strategies may vary sharply between social groups.

Study Design In Unequal Brazil

The research team recruited 1,166 young adults from Northeast Brazil, a region marked by deep economic disparities. The sample included 511 participants from higher socioeconomic backgrounds, mostly university students, and 655 from lower socioeconomic backgrounds, largely public middle and high school students.

Participants were randomly assigned to control or experimental conditions. Those in the experimental group were shown four fabricated profiles of same-sex rivals, with photos and descriptions that varied in physical attractiveness, social skills, and social status.

After viewing the profiles, participants rated their own desirability on a 10-point scale in areas such as appearance, sociability, and financial condition. They also indicated what traits they valued in short-term and long-term romantic partners.

How People Rate Themselves

The study found striking differences in how people from different social classes perceived their strengths. Participants from lower socioeconomic backgrounds rated themselves as more physically attractive than those from wealthier groups.

By contrast, higher socioeconomic participants saw themselves as having better social skills. The authors argue that individuals tend to emphasize the traits that are most available or advantageous in their environment, effectively treating them as social currency.

For those with fewer financial resources, physical appearance may function as a key asset in social and romantic competition. For those with more resources and education, communication skills and networking can be more central to status and success.

Partner Preferences By Class And Sex

Socioeconomic background also shaped what people wanted in long-term relationships. Participants from lower socioeconomic groups placed a stronger emphasis on physical attractiveness in long-term partners than their wealthier counterparts.

Higher socioeconomic participants, on the other hand, prioritized social skills in long-term partners. In stable, resource-rich settings, the ability to navigate social networks and maintain status may be more valuable than appearance alone.

Biological sex still mattered in specific contexts, particularly for short-term relationships. Men showed a stronger preference for physical attractiveness than women when considering casual partners. Women, meanwhile, reported higher preferences for overall attractiveness, social skills, and social status in short-term partners.

Interestingly, both men and women from lower socioeconomic backgrounds prioritized social skills and status in short-term partners more than higher socioeconomic participants did. This suggests that in more precarious environments, even casual relationships are evaluated partly through the lens of resource access and social advantage.

Reactions To Attractive Rivals

The researchers also examined how exposure to highly attractive rivals might shift people’s standards. Rather than broadly lowering self-esteem, the rival profiles tended to fine-tune what certain groups sought in a partner.

One notable pattern emerged among women from lower socioeconomic backgrounds. When they were shown highly attractive female competitors, they increased the importance they placed on a partner’s social status in long-term relationships.

The authors suggest that intense competition over physical attractiveness may push some women to seek security through a partner’s resources and social position. In this way, rivalry can indirectly redirect preferences toward traits that promise stability.

Across all groups, high baseline self-esteem helped buffer against feeling threatened by attractive rivals. Those with stronger self-worth appeared less likely to downgrade their own desirability after viewing idealized competitors.

Limits And Future Research

The study relies on static photos and written descriptions, which cannot fully capture the pressure of real-life social competition. In-person interactions involve body language, immediate feedback, and complex group dynamics that may intensify rivalry and influence choices more strongly.

Mafra cautions that the findings should not be interpreted as proof that rivals have no impact in real scenarios. Instead, she argues that many overlapping factors, from personality to culture, likely shape how people adjust their preferences under social pressure.

The sample also reflects a specific Brazilian context, comparing university students with public school students who often face different career paths and time horizons. These differences may affect how urgently people prioritize stability, resources, or education when choosing partners.

Despite these limitations, the study adds to evidence that men and women are more similar in their romantic psychology than rigid stereotypes suggest. Social conditions, not just biology, appear to play a central role in how people evaluate themselves and others in the dating market.

Mafra is now focusing on LGBTQIA+ mental health, including whether targeted interventions can improve psychological well-being in marginalized communities. She plans to return to research on mating preferences and social context in future projects.

Overall, the study supports a more flexible view of human relationships, where gendered patterns depend strongly on where people live, what they have, and whom they compete with. In an era of rising inequality, understanding these dynamics may be key to explaining how modern dating is evolving.