A simple spritz of a fresh-smelling window cleaner made people more fair and generous in a new study.
The researchers figure cleanliness fosters morality.
They conducted fairness tests, with subjects completing tasks in a room that was either unscented or one that was sprayed with a common citrus-scented window cleaner.
One test involved a game. Study participants were given $12 of real money, which they were told came from an anonymous partner in another room. They had to decide how much of it to either keep or return to their partners who, they were told, had trusted them to divide it fairly.
Subjects in clean-smelling rooms gave back $5.33 on average. The others gave back just $2.81.
"Morality and cleanliness can go hand-in-hand," said study team member Adam Galinsky of the Kellogg School of Management at Northwestern University.
A second experiment asked the subjects' interest in volunteering for a Habitat for Humanity service project. On a 7-point scale, those amid the fresh scent ranked at a 4.21 interest level, on average, while those in the normal room came in at 3.29. Rather just donate money? Sure, said 22 percent of the folks in the fresh-smelling room, compared to only 6 percent in the normal room.
Follow-up questions found the participants didn't notice the scent in the room.
"Researchers have known for years that scents play an active role in reviving positive or negative experiences," Galinsky said. "Now, our research can offer more insight into the links between people's charitable actions and their surroundings."
The study, led by Katie Liljenquist at Brigham Young University, will be detailed in the journal Psychological Science.
Liljenquist and Chen-Bo Zhong at the University of Toronto had previously shown that people who have committed sins feel urged to clean themselves physically. A separate study last year at the University of Plymouth in England found that a vigorous hand wash or shower could cause a person to be less judgmental.
Liljenquist figures businesses could take something from the latest findings:
"Companies often employ heavy-handed interventions to regulate conduct, but they can be costly or oppressive," she said. "This is a very simple, unobtrusive way to promote ethical behavior."
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Robert is an independent health and science journalist and writer based in Phoenix, Arizona. He is a former editor-in-chief of Live Science with over 20 years of experience as a reporter and editor. He has worked on websites such as Space.com and Tom's Guide, and is a contributor on Medium, covering how we age and how to optimize the mind and body through time. He has a journalism degree from Humboldt State University in California.