What do fairy tales have to do with generosity? A new study suggests a lot, as it found that people with a more romantic view of marriage, believing their partner to be a soulmate, are less likely to spend time volunteering.

A study in Sociological Perspectives from Baylor University researchers looked at more than 1,300 couples between 18 and 45 years old and their views on marriage, as well as how often they volunteered, how much time they spent alone together and how often they attended religious services. According to the study, the couples were distinguished by whether they viewed each other as soulmates and made each other their top priority, which accounted for slightly more than half of those surveyed; or whether they equally emphasized other needs and values like raising kids and financial obligations.

“Wives’ soulmate view had a more dampening effect than husbands’ soulmate view on their own and their husbands’ volunteering” — in other words, when the women had a more romantic view of marriage, both the husband and the wife tended to volunteer less, perhaps because the women found the emotional satisfaction they need in their husbands. The man’s romantic view of marriage did not appear associated with volunteering, the study said, and time the couple spent alone with each other in fact appear to have a positive effect on the charitable works.

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The average time spent volunteering was one to two hours in a month.

According to the researchers, their study counters the idea of a “greedy marriage,” in which married people are less likely than singles to practice generosity: “These findings suggest that the greedy nature of marriage is, in part, determined by its participants — how they define and manage their marriage.”

The authors noted the role gender played in their findings, with wives having a stronger effect on volunteer time than husbands. But that may not be surprising when considering that other research has shown women are usually more generous than men with both their time and their money. Data from the U.S. Bureau of Labor Statistics show that in recent years women have consistently volunteered more than men. In September 2015, for example, 27.8 percent of women volunteered, while just 21.8 percent of men did. The numbers are more skewed in the Peace Corps, the international service organization: According to their website, 63 percent of their volunteers are female, although few of their volunteers, male or female, are married.

And Time notes that while large financial donations are often made jointly between men and women, the females more often give monetary donations and volunteer their time. “The difference may be explainable by their motivations,” Time says. “Women are more likely than men to say helping people in need brings them greater happiness than spending money on themselves, and women are more likely to define success by generosity versus wealth.”

One other element the authors expressed surprise over was quality time between husband and wife not diminishing volunteer time. Co-author Young-Il Kim, from Baylor's Institute for Studies of Religion, said in a statement from the university, “One possible explanation is that couples who invest more time in their marriage are more likely to have better relationships, and husbands in such marriages may be more likely to volunteer with their wives, who may push them to volunteer more.”

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