Recent research published in journals evolution and human behavior It has been suggested that, regardless of gender, people experience the strongest romantic jealousy when they see their partner giving resources to a potential rival. This finding provides evidence that transferring resources is viewed as a serious relationship threat by both men and women. This research reveals how our emotional alarm system responds more strongly to a partner actively investing in someone else than to passively receiving attention.
Scientists undertook this study to test traditional evolutionary ideas about human interbreeding in a more realistic setting. Evolutionary theory proposes that men and women face different historical challenges when it comes to reproduction and survival. For early human men, a partner’s sexual infidelity posed the risk of unwittingly raising another man’s child.
For early human women, a partner’s emotional infidelity threatened the loss of their children’s time, protection, and resources. Because of these different historical pressures, scientists suspect that modern men and women trigger jealousy in slightly different ways. Men are often expected to be more responsive to cues of sexual interest from rivals, and women are expected to be more responsive to cues of emotional investment and resource sharing.
Most past research on this topic has been based on simple surveys that ask people to imagine hypothetical cheating scenarios. Scientists wanted to go beyond these imaginary situations and observe real behavior in a controlled environment. “The aim was to test whether romantic jealousy could be evoked in the couple’s economic game paradigm, to extend what is universally seen using the classic forced-choice hypothetical sexual and emotional infidelity scenario,” explained lead researcher Ana María Fernández, professor at the University of Santiago de Chile.
They designed an interactive experiment using real money to see if financial decisions could mimic the ancient threats of resource loss and mate poaching. Mate poaching is a psychological term that describes a situation in which a person intentionally attempts to attract a partner to whom they are already in a committed relationship. “As an experimental psychologist, this allowed us to extend mind-based methods to using experimental economics as a proxy for jealousy induction,” Fernandez said.
To test these ideas, the researchers recruited 79 heterosexual couples for a laboratory experiment. As a result, a total of 158 individual participants were gathered. Participants’ average age was approximately 30 years and had been in a current relationship for at least 6 months.
The couples arrived at the lab together but sat in the same room separated by a physical partition. They then played a computer-based financial exercise known as the Dictator Game. In a standard dictator game, one person is given a certain amount of money, decides how to divide it among others, and the others have no choice but to accept the offer.
In this modified version, participants believed they were interacting online with a real-world partner or a stranger of the opposite sex. The stranger acted as a potential love rival. After each round of the game, participants rated their feelings of jealousy on a scale of 1 to 5.
The researchers created two main experimental scenarios. In the investment scenario, participants observed a partner give 75 percent of the available funds to a rival, leaving only 25 percent for the participant. This was designed to provoke jealousy in women by imitating their partner’s diversion of resources to another woman.
In the receiving scenario, participants observed their partner receiving a large amount of money from a rival. Partners eagerly embraced these resources. This was designed to provoke jealousy in men by imitating a rival trying to steal a partner.
The data revealed that this investment scenario caused the highest level of jealousy among all participants. Both men and women felt very threatened if their partner actively gave money to a rival. “We found that regardless of gender, when a lover allocates more resources to a stranger than to himself, this is a situation where jealousy is created,” Fernandez said.
The researchers noted that actively giving money requires thought, intention, and sacrifice. Therefore, both men and women interpreted this investment scenario as a significant red flag that their partner was leaving. The expected gender differences did not fully emerge in the acceptance scenario.
The researchers predicted that men would be much more jealous than women if their partner received money from a rival. Instead, men and women showed very similar and relatively low levels of jealousy in this situation. “When we tried to model jealousy in men in which their partner received resources from a stranger of the opposite sex, we made it clear that their partner was accepting these resources, but the effect was weak,” Fernandez explained.
The scientists noted that passively accepting money may not send a strong signal of sexual betrayal. A partner may accept resources from a rival just to get free benefits, but this does not necessarily mean they have sexual interest in the rival. To ensure that the jealousy was specifically about one’s own romantic relationships, the researchers also included several control scenarios.
In these control rounds, participants observed random strangers giving and receiving money. Including these additional scenarios allowed the scientists to verify that the jealousy stemmed from a direct threat to the participants’ own romantic bonds. “Besides general jealousy in third-party assignments, we found that some of the control conditions indicated that simply observing unequal assignments or interactions with the opposite sex did not induce jealousy,” Fernandez noted.
She added that this feeling was very specific to relationship threats. “Rather, jealousy is strongest when the transfer of resources involves a clear relational threat; for women, when a partner allocates resources to a female rival,” Fernandez observed. Subtle gender differences emerged during the control scenario.
Women reported feeling jealous when they saw a devoted man give money to a single woman, even if the man was a stranger. This provides evidence that women are generally more wary of how men distribute resources and may treat it as a broader social warning sign. Finally, individual personality traits played an important role in emotional responses.
The scientists asked participants to complete a questionnaire about relationship anxiety. These surveys measured digital jealousy, the anxiety people feel about their online interactions with their partners. They also measured attachment anxiety and attachment avoidance.
Attachment anxiety refers to a deep fear of abandonment and a constant need for reassurance. Attachment avoidance refers to the tendency to distance yourself from others in order to become emotionally independent and avoid vulnerability. Those with higher scores on digital jealousy and attachment anxiety experienced more jealousy across a variety of gaming scenarios.
This suggests that our innate dispositions have a significant impact on how violently we react to relationship threats. Although this experimental design provides a new perspective on romantic emotions, it has several limitations. Lab settings and small exchanges of money may not fully capture the intense pain of real-world betrayal.
Participants may also have adjusted their responses to be more socially acceptable in self-report surveys. Furthermore, the sample consisted mostly of young, educated, heterosexual couples. This limits the extent to which the findings can be applied to older adults, different cultural groups, or non-heterosexual relationships.
Improving experimental conditions is a priority for the research team. “We would like to conclude whether this can be modeled and replicated from the literature on gender differences in jealousy by improving the reception of resources from third parties,” Fernandez said. Tracking couples over time may also help explain how jealousy changes as relationships mature.
The study, “Resource Allocation and Romantic Jealousy: An Experimental Test of Gender Differences Using Economic Games,” was authored by Ana María Fernández, María Teresa Barbato, Michele Dufay, Belén Zavala, and María Luisa Rodríguez Sampaio de Sousa.
