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How to get people to not be slobs in public places

bus interior

Seattle Municipal Archives

How to keep people from leaving their trash behind when they exit busses, subways and trains: citrus-smelling air fresheners.

Remember the research about "classical repulsion" the finding that teenagers can be kept from loitering in public places by broadcasting classical music?

Well, a team of Dutch social psychologists may have come up with an equally simple solution for another public-space quandary: how to keep people from leaving their trash behind when they exit buses, subways and trains.

That solution may be as simple as buying some citrus-smelling air fresheners.

For their study, which was published earlier this month in the journal Social Influence, the Dutch psychologists hid seven small containers of a citrus-smelling cleaning product in the luggage racks of two carriages of a train that was travelling between the cities of Amersfoort-Schothorst and Enkhuizen. After the one-hour-and-45-minute trip was over, the researchers collected, counted, weighed and compared the litter passengers left behind in those carriages with that left behind in two non-scented “control” carriages.

Here’s what they found, as summarized on the British Psychological Society’s "Research Digest" website:

Based on measures taken over 18 journeys, the average amount of rubbish on the unscented carriages was more than three times the weight of the rubbish collected from the scented carriages (35.6 grams vs. 11.7 grams). In terms of individual rubbish items, there were an average of 5.1 in the control carriages per journey vs. 2.7 in the scented carriages.

For comparison, rubbish was also collected from these exact same carriages over several journeys a week or so earlier, prior to the use of the scent (the train company agreed to use the same train on the same route during the period of the study rather than following their usual practice of rotating train stock across different routes). In this case, there was no difference in the amount of litter left in the different carriages.

"It seems to be possible to change the littering behavior of people in a train environment using a simple and relatively cheap intervention," the researchers said.

Maybe I’ll try it in my car.

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Comments (2)


Why does this work, I wonder. And will it work at home. If so, I need to get some citrus air freshener.


People would be more willing to pick up their rubbish if they know they have a place to dispose of it. That's why a lot of women tuck their rubbish in their purses, while men often leave it behind. If there was a waste receptacle in plain sight people would be more inclined to use it. If they don't see one, or have to search for one, they will leave the trash behind.