Men who are more romantically or sexually interested in their female friends tend to pay more for shared expenses, and women interpret this behavior as a sign of interest in marriage, according to a study published in 2016. evolution and human behavior.
Heterosexual friendships are often described as “just friends” relationships, but they can include attraction, romantic potential, or sexual interest. Many people report feeling attraction within a heterosexual friendship, and many romantic relationships begin as friendships. This raises an important question. If interest in marriage is sometimes present in friendships, how is that interest expressed or detected?
Ryan T. Dobson and colleagues investigated whether monetary offerings, such as paying extra for a shared bill, function as courtship behavior in heterosexual friendships. Their study builds on theories that suggest men may be more likely than women to signal romantic or sexual interest by flaunting their resources or generosity, in part because women have historically placed greater value on a partner’s willingness and ability to invest resources. The researchers also tested another explanation. Perhaps financial preparedness reflects how valuable or high-quality people perceive their friendships to be, rather than their interest in marriage.
The study involved 581 undergraduate students from a university in the southwestern United States. Participants completed an anonymous online survey during the Spring 2024, Fall 2024, and Spring 2025 semesters. Given that the study focused on heterosexual friendship relationships, participants who failed data quality checks or who reported being asexual or homosexual were excluded from the analysis. The final sample was mostly female, with a mean age of 21.3 years.
Participants answered questions about their closest opposite-sex friend and second-closest opposite-sex friend, excluding current romantic partners and family members. They completed an 11-item measure of their own romantic and sexual interest in each friend, a three-item measure of how interested each friend was in them, a payment item using a scale of 1 to 7 where a higher score meant the participant would pay more, and an eight-item measure of friendship quality using a consensus scale of 1 to 7.
Because participants reported on two friends, the researchers were able to test both interpersonal effects, such as whether some men generally pay more beyond friendships, and intrapersonal effects, such as whether men pay more for specific female friends to whom they are more attracted.
Dobson et al. found that both men and women reported sexist patterns in paying their bills. Men said their female friends paid more of their bills, while women said their male friends paid more of their bills. This replicates previous research suggesting that financial provision from men to women is more common in heterosexual friendships.
Key findings supported the idea that financial provision can act as a courtship signal in friendships. Men who reported higher overall mating interest in their female friends also reported paying more of their bills. This pattern did not emerge similarly among women. Women’s mating interest did not predict greater financial provision, and women who were more interested in male friends actually reported paying less.
Friendship quality also did not predict financial preparedness. Participants who viewed opposite-sex friendships as more supportive, enjoyable, emotionally close, valuable, or difficult to replace did not tend to pay greater cost burdens, providing no support for the alternative hypothesis.
Women also seem to interpret men’s financial help as a sign of interest. Women whose male friends paid more bills perceived their male friends to be more interested in mating with them. However, men did not show the same pattern when their female friends paid more.
Importantly, the effects were primarily between-individuals rather than within-individuals. The findings did not show that the same men would pay more for the particular female friends they liked the most. Rather, some men were more likely than others to view heterosexual friendships as mating opportunities and to pay more through them.
Of note, this study is cross-sectional and relies on self-report, so it cannot prove that men intentionally paid more to express interest in mating or that women inferred interest because of their paying behavior. Because this sample included young people in college, the results may not be generalizable to older adults or different cultural backgrounds.
Overall, the findings suggest that heterosexual friendships are not equally platonic for everyone, and that financial generosity may be a way to express and acknowledge mateship interest in some male-female friendships.
The study, “Courtship in Heterosexual Friendships: A New Test of Male Economic Supply as Signals and Signals of Mating Interest,” was authored by Ryan T. Dobson, William Costello, and David MG. Lewis.
