Two studies using hypothetical money distribution tasks found that people were generally more concerned about a potential partner’s generosity than their wealth. However, as differences in potential partners’ generosity increased, preferences for generosity increased. Conversely, as wealth differences increased, the tendency to seek generosity decreased. This study evolution and human behavior.
Whether in friendship, business, or love, choosing the right partner has played a major role in the evolution of human cooperation. When people can decide who they interact with, they tend to prefer people who are kind and trustworthy, promoting cooperative behavior overall. In this type of “social market,” individuals generally try to show that they are generous or trustworthy in order to attract good partners.
A good partner is one who brings benefits while causing few problems or costs. In everyday terms, people usually judge this based on how kind the person is (warmth), how competent or successful the person is (competency), and whether or not they can actually help. Kindness and competence are both important, but which one is more important depends on the situation and environment.
Importantly, there is little point in evaluating qualities that everyone has equally, so people pay more attention to characteristics that differ markedly between individuals. Research using computer simulations shows that people develop stronger preferences for kindness when kindness varies widely within a group, and the same pattern holds true for ability.
Study authors Yuta Kawamura and Pat Barclay wanted to investigate whether people value their partners’ generosity more when their partners differ in their willingness to donate, or whether they value their partners’ wealth more when their partners differ in their ability to donate. They conducted two online studies in which participants were presented with a pool of virtual partners for a money sharing task.
The initial study included 350 U.S. residents recruited through CloudResearch from Amazon Mechanical Turk. The average age was 40 years, and 163 of the participants were women.
Participants were randomly divided into two groups. To establish an environmental “baseline,” both groups were shown information about how 20 potential partners had previously shared money.
In the “unequal generosity” group, all 20 potential partners had approximately the same total amount (149–149–151) but differed in the percentage of the amount they contributed (ranging from 3% to 56%). In the “unequal wealth” group, all potential partners contributed about the same percentage of their money (29% to 31%), but the total amount they had varied (ranging from $16 to $280). Importantly, the absolute amount actually distributed was the same in both conditions. Only differences in wealth and generosity have changed.
Participants were then asked to choose a new partner for themselves. But before making their choice, they had to decide what information they wanted to know about their future partner. It can be wealth (total monetary wealth) or generosity (shared proportion).
The second study involved 600 Americans, also recruited through CloudResearch. The procedure was the same as in the first study, with one important addition. The authors introduced a third “control” group. In this group, participants were not shown how potential partners had behaved in the past. That is, there was no information about how much wealth or generosity changed within the population.
The results of the first study showed that participants were generally more interested in a potential partner’s generosity than their own wealth. However, the environment was very important. In groups where potential partners differed in their generosity, participants were more likely to seek information about generosity (82%). However, in the group where the wealth of potential partners varied, the desire to know about generosity decreased significantly (down to 55%) as the majority of participants shifted their focus to knowing their partner’s wealth.
A second study confirmed these findings and revealed the human “default.” The proportion of people interested in generosity did not differ significantly between the unequal generosity group (90%) and the control group (87%). However, when participants knew that their partners’ wealth differed significantly, they were much less likely to choose to see information about generosity (61%).
“Participants had a default preference to know more about the generosity of others than about their own wealth. This preference was strengthened when there was greater dispersion in others’ generosity, and weakened when there was greater dispersion in others’ wealth,” the study authors concluded. “Thus, our study shows that people are sensitive to the amount of population variance in a trait and flexibly adjust their partner preferences to focus on traits that vary more among other traits.”
This study contributes to scientific knowledge regarding psychological factors that influence partner selection. However, the authors noted some limitations. The study asked hypothetical questions rather than having participants hand out actual money, and the study was conducted within a single culture (the United States).
Furthermore, it should be noted that “wealth” in this experimental context is operationalized as the size of a temporary monetary fortune (up to $280) in an economic game, rather than real-world accumulated wealth, status, or net worth. Future research may be needed to determine how these flexible partner preferences affect real-world macroeconomic wealth differences.
The paper, “Wealth or generosity? People choose partners based on which is more volatile,” was written by Yuta Kawamura and Pat Barclay.

