What is the Broken Glass Theory?

The broken glass theory states that any visible signs of crime and civil disorder, such as broken windows (hence, the name of the theory) create an urban environment that promotes even more crime and disorder.

The theory was introduced in a 1982 article by social scientists James Q. Wilson and George L. Kelling. It was further popularized in the 1990s by New York City police commissioner William Bratton and Mayor Rudy Giuliani, whose policing policies were influenced by the theory.

As such, policing these misdemeanors will help create an ordered and lawful society in which all citizens feel safe and crime rates, including violent crime rates, are low

Broken windows policing has become associated with controversial police practices, such as the high use of stop-and-frisk in New York City in the decade up to 2013. In response, Bratton and Kelling have written that broken windows policing should not be treated as “zero tolerance” or “zealotry”, but as a method that requires “careful training, guidelines, and supervision” and a positive relationship with communities, thus linking it to community.

The broken glass experiment

In 1969, Stanford psychologist Philip Zimbardo ran a social experiment in which he abandoned two cars that had no license plates and the hoods up in very different locations. The first was a predominantly poor, high-crime neighborhood in the Bronx, and the second was a fairly affluent area of Palo Alto, California. He then observed two very different outcomes.

After just ten minutes, the car in the Bronx was attacked and vandalized. A family first approached the vehicle and removed the radiator and battery. Within the first twenty-four hours after Zimbardo left the car, everything valuable had been stripped and removed from the car.

Afterwards, random acts of destruction began – the windows were smashed, seats were ripped up, and the car began to serve as a playground for children in the community. On the contrary, the car that was left in Palo Alto remained untouched for more than a week before Zimbardo eventually went up to it and smashed the vehicle with a sledgehammer.

Only after he had done this did other people join the destruction of the car (Zimbardo, 1969). Zimbardo concluded that something that is clearly abandoned and neglected can become a target for vandalism.