Heterosexual and homosexual individuals value altruism equally in potential mates

A recent study published in Evolutionary Psychological Science examined whether sexual orientation influences the desirability of altruism in a potential romantic partner. The researchers found that altruistic behavior is universally attractive, with no significant differences between heterosexual and homosexual participants in how much they valued altruistic traits in a mate. The findings suggest that altruism is a broadly appealing quality in human relationships.

Previous research has demonstrated that altruistic behaviors, such as volunteering or helping others without expecting personal gain, are considered desirable traits in long-term partners. These behaviors are thought to signal good parenting potential and social cooperation—traits that have evolutionary benefits. However, existing studies on altruism and attraction have predominantly focused on heterosexual participants, leaving questions about how these findings apply to same-sex relationships.

“Interest in the evolutionary psychological approach to same-sex romantic attraction began during my undergraduate degree at the University of Wolverhampton,” said study author Aaron Duxbury, who is now a postgraduate research student.

“Dr. Manpal Singh Bhogal (my co-author on this paper) gave a lecture, giving a broad overview of evolutionary psychology. During the session, mate choice was discussed and particularly altruism. I noticed that same sex couples were not included in any of the data presented.”

“I have always felt a strong sense of justice and hate to see any one particular group ignored or overlooked in some way, so I asked why recruitment has not previously included same sex attracted participants. Manpal told me no one has looked into it yet, so I decided there and then that my future in research would be along these lines.”

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The study involved 321 participants recruited from the United Kingdom, consisting of 215 self-identified heterosexual individuals and 106 self-identified homosexual individuals. Participants completed two standardized self-report measures online: the Mate Preferences Towards Altruistic Traits (MPAT) scale and a modernized version of the Self-Report Altruism (SRA) scale. These scales assessed how desirable participants found altruistic behaviors in potential partners and how altruistic they considered themselves to be.

The MPAT scale presented participants with scenarios describing altruistic actions, such as volunteering to help people with disabilities, and asked them to rate the desirability of each behavior on a scale from 1 (undesirable) to 5 (very desirable). To minimize bias, the questionnaire included neutral filler questions that did not involve altruistic acts. Meanwhile, the SRA scale required participants to evaluate their own altruistic tendencies by rating how often they performed specific prosocial actions, such as giving directions to strangers.

The researchers found that altruistic behavior is a desirable trait in potential mates for both heterosexual and homosexual individuals, with no significant differences between the two groups. Interestingly, while previous studies have suggested that homosexual individuals might exhibit greater altruistic tendencies, the current study found that heterosexual participants reported slightly higher levels of self-rated altruism. This finding challenges some prior theories that link same-sex sexual attraction to increased prosociality, suggesting that altruistic behavior may function similarly across different sexual orientations in the context of mate selection.

“I found the non-significant result in sexual orientation a surprise,” Duxbury told PsyPost. “It was theorized by Barron & Hare (2020) that homosexuality in humans had evolved in order to strengthen social bonds between community groups via prosocial acts, so had hypothesized that homosexual participants would place higher importance on altruism than their heterosexual counterparts. However, this was not the case.”

The researchers also found that female participants, regardless of sexual orientation, rated altruistic traits more highly than male participants. Additionally, individuals who rated themselves as highly altruistic tended to find altruistic traits in others more desirable.

“Broadly speaking, altruism (or selfless acts) is a desirable trait across heterosexual or homosexual participants,” Duxbury explained. “We know from existing research (Moore et al., 2013) that females place higher importance on altruism than males, a finding supported in this research piece. This would potentially suggest that altruism is an evolved trait to indicate good partner/parent quality, which would align regardless of sexual orientation as same-sex couples can still have offspring, albeit not naturally occurring (Farrelly, 2013).”

But the study, like all research, includes some caveats.

“This study focused on heterosexual or homosexual participants in male or female categories. This means that other gender expressions or sexualities such as bisexual participants, for example, have not been accounted for,” Duxbury noted. “We also did not discriminate between short-term and long-term relationships, existing research demonstrates that trait preferences are different for short- and long-term relationships (Bhogal et al., 2020).”

Despite these limitations, the study represents an important step toward understanding the role of altruism in mate selection across diverse populations. Future research could explore additional factors to determine how these traits interact with altruism in shaping romantic preferences among same-sex and opposite-sex attracted individuals.

“This research is the first study to explore altruism in same sex attraction through an evolutionary lens, and I wish for this exploratory work to continue,” Duxbury said. “Future work will hopefully include areas such as heroism, physical attractiveness, their role in attraction for same sex attracted persons and if this differs from existing research into heterosexual participants. I also hope to accommodate the limitations of this present study to further research in this area and make it as inclusive as possible.”

The study, “The Effect of Sexual Orientation on Preferences for Altruism in Human Mate Choice,” was authored by Aaron Duxbury and Manpal Singh Bhogal.