"Philip Zimbardo, a Stanford psychologist, reported in 1969 on some experiments testing the broken-window theory. He arranged to have an automobile without license plates parked with its hood up on a street in the Bronx and a comparable automobile on a street in Palo Alto, California. The car in the Bronx was attacked by "vandals" within ten minutes of its "abandonment." The first to arrive were a family -- father, mother, and young son -- who removed the radiator and battery. Within twenty-four hours, virtually everything of value had been removed. Then random destruction began -- windows were smashed, parts torn off, upholstery ripped. Children began to use the car as a playground. Most of the adult "vandals" were well dressed, apparently clean-cut whites. The car in Palo Alto sat untouched for more than a week. Then Zimbardo smashed part of it with a sledgehammer. Soon, passersby were joining in. Within a few hours, the car had been turned upside down and utterly destroyed. Again, the 'vandals" appeared to be primarily respectable whites.

Untended property becomes fair game for people out for fun or plunder, and even for people who ordinarily would not dream of doing such things and who probably consider themselves law-abiding.  Because of the nature of community life in the Bronx -- its anonymity, the frequency with which cars are abandoned and things are stolen or broken, the past experience of "no one caring" -- vandalism begins much more quickly than it does in staid Palo Alto, where people have come to believe that private possessions are cared for, and that mischievous behavior is costly. But vandalism can occur anywhere once communal barriers -- the sense of mutual regard and the obligations of civility -- are lowered by actions that seem to signal that "no one cares.""