There are new signs that fighting urban decay by “greening” abandoned lots will deter crime and make residents feel safer. Vacant lots are often littered and grubby, and they contribute to criminality by serving as areas to stash illegal weapons, perform drug sales, and violence. A recent study showing this correlation provides renewed support for the Broken Windows idea promoted by the late sociologist James Q. Wilson and his colleague George L. Kelling, who argued that there is indeed a connection between disorder and crime.
The Broken Windows theory is rooted in research on disorder that began in 1969. Stanford psychologist Philip Zimbardo conducted an experiment where he left a car without license plates and its hood up on the street in Bronx, New York. He left a comparable car on a street in Palo Alto, California. Results showed that the Bronx car was damaged within minutes and demolished within 24 hours. The Palo Alto car remained intact for a week until Zimbardo smashed it with a sledgehammer, ultimately achieving the same outcome as the car in the Bronx. Partially based on the results of such experimentation, Wilson and Kelling introduced the Broken Windows theory in 1982, which states that failure to enforce laws against minor public order offenses presents risks for serious crime.
In the recent study by the Perelman School of Medicine at the University of Pennsylvania, greening consisted of cleaning old lots, planting grass and trees, and building a wooden fence around the perimeter. The authors concluded that while a larger randomized controlled trial is necessary to further investigate the link between vacant lot greening and violence reduction, they observed that greening was associated with reductions in certain gun crimes and improvements in residents' perceptions of safety. Who would have thought that greening might serve as an effective method of restoring order and preventing crime?