In 2008, a research team led by environmental psychologist Kees Keizer at the University of Groningen carried out a series of revealing experiments focused on the impact of environmental disorder on norm-breaking actions. The experiments, conducted in Groningen, the Netherlands, sought to determine whether witnessing a breached social norm would heighten the chances of individuals later violating an unrelated norm.
One of the tests involved positioning a stamped envelope with a clearly visible five-euro note protruding from a public mailbox. The results were revealing: 13 percent of passersby claimed the envelope when the mailbox and its vicinity were tidy, but this number jumped to 27 percent when the mailbox was defaced with graffiti and to 25 percent when the ground was strewn with litter.
In a different experiment, flyers were affixed to bicycle handlebars in an alley marked by a no-graffiti sign. With the alley in a clean state, 33 percent of cyclists discarded the flyer on the ground, whereas this number surged to 69 percent in the presence of graffiti on the walls. Comparable trends were observed in other scenarios, such as a supermarket parking lot with forsaken carts and a construction detour featuring bicycles improperly locked to the fence, where evident deviations from norms prompted increased norm-breaking behavior.
Notably, these results differ from the broader notion of “broken windows policing,” which contends that addressing minor disorders mitigates severe crime. Although this latter theory has encountered criticism and scrutiny when accounting for variables like poverty, Keizer’s experiments specifically examine whether individuals are more inclined to violate rules after witnessing another broken rule in proximity. This more focused hypothesis presents a clear perspective on how descriptive norms influence actions.
Keizer’s research indicates that visible signs of one broken rule may lead individuals to assume that rules, in general, are less likely to be enforced. It’s less about disorder directly inciting crime and more about perception shaping behavior; when an environment appears orderly, people are more aware of adhering to rules, as neat settings suggest that norms are being upheld and anticipated.
While the experiments occurred in a single city with subjects unaware of being observed, the implications extend further—evident tidiness serves as a social cue, influencing behavior in ways that a mere written rule may not. This finding, based on practical experiments, offers valuable insights into how environmental signals can subtly influence normative conduct.