Does graffiti make you a delinquent person? A new Dutch study led by Kees Keizer of the University of Groningen suggests it just might:

His [Dr Keizer] group’s first study was conducted in an alley that is frequently used to park bicycles. As in all of their experiments, the researchers created two conditions: one of order and the other of disorder. In the former, the walls of the alley were freshly painted; in the latter, they were tagged with graffiti (but not elaborately, to avoid the perception that it might be art). In both states a large sign prohibiting graffiti was put up, so that it would not be missed by anyone who came to collect a bicycle. All the bikes then had a flyer promoting a non-existent sports shop attached to their handlebars. This needed to be removed before a bicycle could be ridden.

When owners returned, their behaviour was secretly observed. There were no rubbish bins in the alley, so a cyclist had three choices. He could take the flyer with him, hang it on another bicycle (which the researchers counted as littering) or throw it to the floor. When the alley contained graffiti, 69% of the riders littered compared with 33% when the walls were clean.