Tuesday, 27 March 2012

Passengers litter less on carriages that smell of cleaning product

A team of Dutch social psychologists has proposed a simple solution to the litter problem on trains - infuse carriages with the citrus scent of cleaning product. Martinijn de Lange and his colleagues made their recommendation after conducting a field experiment in which they concealed seven small containers of cleaning product (spiced up with a little Capitaine perfume oil) in the luggage racks of two carriages on a train travelling between Amersfoort-Schothorst and Enkhuizen, a journey of one hour and forty-four minutes.

The amount of rubbish not in bins on these two carriages was collected at the final stop, counted and weighed and compared with the amount of rubbish left in two, scent-free control carriages. 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 behaviour of people in a train environment using a simple and relatively cheap intervention," the researchers said.

Why should the scent of cleaning product have had this effect on passengers' littering behaviour? de Lange and his colleagues think the effect probably occurs via the non-conscious priming of cleaning related motives and behaviours. Supporting this account, a 2005 lab study (pdf) reported that exposing participants discreetly to the smell of citrus cleaning product led them to list more cleaning-related activities in their plans for the day and to spill fewer crumbs when munching on a cookie. "The positive results of our scent manipulation in a field setting provide support for the idea that the cognitive route of scents to behaviour can be used as a tool for behavioural change," de Lange and his team said. "Merely dispersing a scent seems to trigger related goals and influence subsequent behaviour."

Alternatively, perhaps passengers grew sick of the citrus smell and simply avoided sitting in the scented carriages! That would explain a surprising finding I didn't mention earlier - that rubbish in the non-scented carriages (but not the scented ones) was higher during the intervention period than during the earlier comparison weeks. The researchers put that down to the intervention weeks being busier than the comparison weeks, leading to more rubbish in the non-scented carriages (but not in the scented carriages because of the behavioural effect of the scent).

 _________________________________ ResearchBlogging.org

de Lange, M., Debets, L., Ruitenburg, K., and Holland, R. (2012). Making less of a mess: Scent exposure as a tool for behavioral change. Social Influence, 7 (2), 90-97 DOI: 10.1080/15534510.2012.659509

Post written by Christian Jarrett for the BPS Research Digest.


Andrew said...

The power of smell is pretty crazy! Smell must have a short cut to manipulating our behavior, because it has an easier time getting us to do what it wants better than we can do consciously ourselves. Maybe it is an evolutionary adaptation to allow us to conform quickly without making it too difficult with the ever so finicky cognition.

Anonymous said...

Would it work in a house of messy students??

Anonymous said...

I find this interesting and awesome! From my personal experience on a train, they are definitely not the cleanest form of transportation. It makes sense that if the passengers feel as though they are in a clean environment, that they are more likely to keep it that way. However, most trains usually have a funky smell and the bathrooms often seem unkept and dirty. The cleaning supplies smell implies that the people who are employed to keep the train clean are working hard, therefore the passengers probably want to show appreciation by keeping it clean.

Jon Plump said...

I find this article extremely interesting. We are learning about this very subject in PSY-101 class. In this section, we have been learning about "learning" and ways to enforce behaviors on different people. The psychologist used operant conditioning in order to decrease the act of littering. Reinforcement is said to occur when a stimulus or an event follows an operant and increases the likelihood of the operant being repeated. The citrus scent would be the operant and the nauseating feeling is the reinforcing stimulus. In order to avoid getting sick from the citrus smell, the passengers would avoid sitting in those areas.

Anonymous said...

I Loved this article so much, that I;ve posted a link on my new Smell and the City blog http://smellandthecity.wordpress.com/

Megan Iskra said...

The experimenters attempted to use the citrus cleaning scent as an unconditioned stimulus to influence the passengers to throw away their trash rather than littering. It was interesting to see that the passengers on the citrus scented carriages learned to throw away their trash, probably not even realizing that the scent had influenced them. The outcome of litter on the scented carriages was 3 times less than the unscented carriages!

Rab_Admin said...

Utter nonsense ! I work for a firm that takes care of cleaning trains and busses in The Netherlands, litter generally varies from day to day, we have tried many experiments to determine when people are more likely to drop litter as opposed to using the garbage containers, all we found was that litter was much more frequent on or around public holidays, and our trains were only just last week (April 2012) praised by an independent controller working the entire country as "The cleanest trains in the country" I might add, that the biggest problem on dutch trains is chewing gum, you will find it literally everywhere !

Anonymous said...

that is the same question I am interested in too

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