In a study currently in press at the journal Psychological Science, the researchers concluded that individuals in a room spritzed with a citrus-scented cleaning product were more generous when playing trust games.
The team, led by Professor Liljenquist at the Brigham Young University, Utah, recruited 28 participants. Half were assigned a clean scented room and the other half in a non-scented room and all were engaged in an anonymous trust game.
In theory, the game involves two players, the sender and a receiver. The sender is given a certain amount of money that he can invest, if he wishes, with the receiver. Whatever he gives to the receiver will be tripled and this new figure is divided up between the two players as the receiver sees fit.
Both participants will win (end up with more than they had at the start of the game) if the sender sends all the money and the receiver divides the tripled total equally.
However, participants in this study were all told they were playing the role of the receiver and that the sender had decided to send all of the money to them.
The total was tripled and the receiver then had to decide how much he or she wanted to give back to the sender; or, in the words of the study authors, how much he or she wanted to ‘honor the sender’s trust’.
According to the study, participants in the clean-scented room returned significantly more money than those in the non-scented room.
“The clean-scented room led participants to resist exploitation and reciprocate the trusting behavior of the sender,” concluded the scientists.
In addition, the team performed a further experiment that was designed to investigate the clean scent on the willingness of an individual to perform a future charitable act.
In this experiment, 99 undergraduates were again divided between the two rooms and asked to work on a collection of unrelated tasks. One of the tasks was completing a flier from a charity asking for volunteers and funds.
The scientists claim that individuals in the clean-scented room expressed greater interest in volunteering and a higher proportion agreed to donate funds, than those in the non-scented room.
In order to investigate whether it was simply a feeling of wellbeing promoted by the clean scent that was responsible for the more charitable behavior, the participants answered a shortened PANAS questionnaire (a survey used as a measure of psychological well being). According to the study, PANAS results did not differ from room to room.
For the researchers, these changes in behavior can be explained by a symbolic link in individuals’ minds between moral purity and cleanliness, epitomised, according to the researchers, by the ‘cleanliness is next to godliness’ adage.
However, psychologist at Brown University Rachel Herz, quoted in Time Magazine, argued that a third room should have been added to the experiment with another ‘positive’ smell such as freshly baked cookies, in order to be able to rule out the well-being factor conclusively, and conclude it was cleanliness.