Broken windows theory: why code quality and simplistic design are non-negotiable

Mar 27, 2019 · 3 min read

A friend once told me about an experiment where someone left a new car in the street — it remained there untouched for a week.

They repeated the experiment again, but this time they made a deliberate crack in the windscreen of the car, and within a few days, the car was completely burnt out.

The broken windows theory is a criminological theory that visible signs of crime, anti-social behavior, and civil disorder create an urban environment that encourages further crime and disorder, including serious crimes. The theory suggests that policing methods that target minor crimes such as vandalism, public drinking, and fare evasion help to create an atmosphere of order and lawfulness, thereby preventing more serious crimes. — Wikipedia

Each person who damaged the car didn’t really change the state of it very much. The window was already cracked, so somebody just added another crack; no big deal. Compare this to making the first crack in an otherwise pristine car — the difference is significant.

Later, somebody else comes along and does some other small amount of damage to the already-damaged car, and so on until it is a wreck.

If we think about the Broken windows theory when it comes to code and software design, it’s clear that there is great value in the cost of maintaining quality.

If you work on a project that has flaky tests, then you’re more likely to add more flaky tests. If there is a hacky design, you’re more likely to hack more in. If there is a package called utils , you’re more likely to stick more utilities in there. If one of your HTTP handlers uses a global variable for some state, why wouldn’t yours? If anything, we’re taught that our projects should be self-similar and consistent — so maybe we’re even doing the right thing?

Each person who contributes to this mess isn’t really changing the system much, but they are headed towards a fire.

Like in the criminology theory, policing the small stuff and taking the time to keep the quality of your projects high ought to be one the highest priorities of the team. This can include refactoring, developer documentation, good and clear Makefiles, simple package layout, good quality test code, and more. None of these things should be overdone, they should be as simple as they can be (but no simpler, right Einstein?).

Isn’t perfection the enemy of progress?

No project is going to be perfect, and there will always be things we’re not happy with as a team but that “just aren’t worth fixing.” It’s important to be honest (and positive) about this fact. Complaining might be good therapy for developers, but a team deciding to leave something the way it is for the sake of progress is a respectable position to take; and should be a positive experience and an excuse for learning.

Limiting scope is a great way to ensure teams have the time they need to get the important stuff right and this needs to be understood across the entire company (not just the dev team). Maybe our software doesn’t do everything, but what it does do, it does well.

Conclusion

Remember the Broken window theory when you next mark a ticket as ‘done’. Have you just made the first crack in an otherwise pristine window? If so, get some help from the team and take a little more time to refactor it until you’re happy that it meets your standards.

When reviewing code, police the small stuff. Pay attention to the implied decisions and make sure you’re happy with the decisions (overt or otherwise) that are being taken along the way.

What Is the Broken Windows Theory?

The broken windows theory states that visible signs of crime in urban areas lead to further crime. The theory is often associated with the 2000 case of Illinois v. Wardlow, in which the U.S. Supreme Court confirmed that the police, based on the legal doctrine of probable cause, have the authority to detain and physically search, or “stop-and-frisk,” people in crime-prone neighborhoods who appear to be behaving suspiciously.

Key Takeaways: Broken Windows Theory

• The broken windows theory of criminology holds that visible signs of crime in densely-populated, lower-income urban areas will encourage additional criminal activity.
• Broken windows neighborhood policing tactics employ heightened enforcement of relatively minor “quality of life” crimes like loitering, public drinking, and graffiti.
• The theory has been criticized for encouraging discriminatory police practices, such as unequal enforcement based on racial profiling.

Broken Windows Theory Definition

In the field of criminology, the broken windows theory holds that lingering visible evidence of crime, anti-social behavior, and civil unrest in densely populated urban areas suggests a lack of active local law enforcement and encourages people to commit further, even more serious crimes.

The theory was first suggested in 1982 by social scientist, George L. Kelling in his article, “Broken Windows: The police and neighborhood safety” published in The Atlantic. Kelling explained the theory as follows:

“Consider a building with a few broken windows. If the windows are not repaired, the tendency is for vandals to break a few more windows. Eventually, they may even break into the building, and if it’s unoccupied, perhaps become squatters or light fires inside.

“Or consider a pavement. Some litter accumulates. Soon, more litter accumulates. Eventually, people even start leaving bags of refuse from take-out restaurants there or even break into cars.”

Kelling based his theory on the results of an experiment conducted by Stanford psychologist Philip Zimbardo in 1969. In his experiment, Zimbardo parked an apparently disabled and abandoned car in a low-income area of the Bronx, New York City, and a similar car in an affluent Palo Alto, California neighborhood. Within 24 hours, everything of value had been stolen from the car in the Bronx. Within a few days, vandals had smashed the car’s windows and ripped out the upholstery. At the same time, the car abandoned in Palo Alto remained untouched for over a week, until Zimbardo himself smashed it with a sledgehammer. Soon, other people Zimbardo described as mostly well dressed, “clean-cut” Caucasians joined in the vandalism. Zimbardo concluded that in high-crime areas like the Bronx, where such abandoned property is commonplace, vandalism and theft occur far faster as the community takes such acts for granted. However, similar crimes can occur in any community when the people’s mutual regard for proper civil behavior is lowered by actions that suggest a general lack of concern.

Kelling concluded that by selectively targeting minor crimes like vandalism, public intoxication, and loitering, police can establish an atmosphere of civil order and lawfulness, thus helping to prevent more serious crimes.

Broken Windows Policing

In1993, New York City Mayor Rudy Giuliani and police commissioner William Bratton cited Kelling and his broken windows theory as a basis for implementing a new “tough-stance” policy aggressively addressing relatively minor crimes seen as negatively affecting the quality of life in the inner-city.

Bratton directed NYPD to step up enforcement of laws against crimes like public drinking, public urination, and graffiti. He also cracked down on so-called “squeegee men,” vagrants who aggressively demand payment at traffic stops for unsolicited car window washings. Reviving a Prohibition-era city ban on dancing in unlicensed establishments, police controversially shuttered many of the city’s night clubs with records of public disturbances.

While studies of New York’s crime statistics conducted between 2001 and 2017 suggested that enforcement policies based on the broken windows theory were effective in reducing rates of both minor and serious crimes, other factors may have also contributed to the result. For example, New York’s crime decrease may have simply been part of a nationwide trend that saw other major cities with different policing practices experience similar decreases over the period. In addition, New York City’s 39% drop in the unemployment rate could have contributed to the reduction in crime.

In 2005, police in the Boston suburb of Lowell, Massachusetts, identified 34 “crime hot spots” fitting the broken windows theory profile. In 17 of the spots, police made more misdemeanor arrests, while other city authorities cleared trash, fixed streetlights, and enforced building codes. In the other 17 spots, no changes in routine procedures were made. While the areas given special attention saw a 20% reduction in police calls, a study of the experiment concluded that simply cleaning up the physical environment had been more effective than an increase in misdemeanor arrests.

Today, however, five major U.S. cities—New York, Chicago, Los Angeles, Boston, and Denver—all acknowledge employing at least some neighborhood policing tactics based on Kelling’s broken windows theory. In all of these cities, police stress aggressive enforcement of minor misdemeanor laws.

Critics

Despite its popularity in major cities, police policy based on the broken windows theory is not without its critics, who question both its effectiveness and fairness of application.

In 2005, University of Chicago Law School professor Bernard Harcourt published a study finding no evidence that broken windows policing actually reduces crime. “We don’t deny that the ‘broken windows’ idea seems compelling,” wrote Harcourt. “The problem is that it doesn’t seem to work as claimed in practice.”

Specifically, Harcourt contended that crime data from New York City’s 1990s application of broken windows policing had been misinterpreted. Though the NYPD had realized greatly reduced crime rates in the broken windows enforcement areas, the same areas had also been the areas worst affected by the crack-cocaine epidemic that caused citywide homicide rates to soar. “Everywhere crime skyrocketed as a result of crack, there were eventual declines once the crack epidemic ebbed,” Harcourt note. “This is true for police precincts in New York and for cities across the country.” In short, Harcourt contended that New York’s declines in crime during the 1990s were both predictable and would have happened with or without broken windows policing.

Harcourt concluded that for most cities, the costs of broken windows policing outweigh the benefits. “In our opinion, focusing on minor misdemeanors is a diversion of valuable police funding and time from what really seems to help—targeted police patrols against violence, gang activity and gun crimes in the highest-crime ‘hot spots.’”

Broken windows policing has also been criticized for its potential to encourage unequal, potentially discriminatory enforcement practices such as racial profiling, too often with disastrous results.

Arising from objections to practices like “Stop-and-Frisk,” critics point to the case of Eric Garner, an unarmed Black man killed by a New York City police officer in 2014. After observing Garner standing on a street corner in a high-crime area of Staten Island, police suspected him of selling “loosies,” untaxed cigarettes. When, according to the police report, Garner resisted arrest, an officer took him to the ground in a chock hold. An hour later, Garner died in the hospital of what the coroner determined to be homicide resulting from, “Compression of neck, compression of chest and prone positioning during physical restraint by police.” After a grand jury failed to indict the officer involved, anti-police protests broke out in several cities.

Since then, and due to the deaths of other unarmed Black men accused of minor crimes predominantly by white police officers, more sociologists and criminologists have questioned the effects of broken windows theory policing. Critics argue that it is racially discriminatory, as police statistically tend to view, and thus, target, non-whites as suspects in low-income, high-crime areas.

According to Paul Larkin, Senior Legal Research Fellow at the Heritage Foundation, established historic evidence shows that persons of color are more likely than whites to be detained, questioned, searched, and arrested by police. Larkin suggests that this happens more often in areas chosen for broken windows-based policing due to a combination of: the individual’s race, police officers being tempted to stop minority suspects because they statistically appear to commit more crimes, and the tacit approval of those practices by police officials.

Broken windows theory

The Broken windows theory was created by Philip Zimbardo and states that signs of neglect can encourage further neglect and destruction. It is the basis of one of the biggest theories in policing.

Contents

The experiment [ edit ]

This theory was developed based on an experiment where two cars were parked without their licence plates and their hoods up in two different urban environments, one in a poor and crime-ridden section of New York City while the other was parked in a rich neighborhood in California. The New York car was destroyed in 10 minutes while the California car lasted over a week. Then Zimbardo took a sledgehammer to the California car and it was taken apart soon after just like the New York car. [1]

Idea in criminology [ edit ]

Later on, criminologists George L. Kelling and James Q. Wilson decided to take the Zimbardo experiment and apply it to a societal level. Their idea is that as soon as signs of disorder appear in a neighborhood it’s only a matter of time before the neighborhood falls apart. They considered signs of disorder to be visible crimes such as drug use or prostitution, defacing the environment with graffiti and even loitering. The idea was that if you can get the police department to get these signs of disorder addressed it will prevent bigger crimes. [2]

This idea had a large effect in American policing policy, particularly in New York City where William Bratton was convinced to focus on misdemeanours and turnstile jumpers and subway crime seemed to decrease dramatically. By 1994 he became the police commissioner and extended the same idea to patrolling police officers, cracking down on disorderly behaviour such as pan handling and public drinking. [3]

Effects [ edit ]

Despite the glowing recommendations by various proponents there has been little to no proof that reducing signs of disorder cause any reduction in more serious crime. In the locations it was tested in there was a much higher crime rate due to the 1980s crack epidemic and the effect that was thought to be from broken windows policing was actually crime reducing to its normal levels.

A later experiment looked at two groups of people, one that stayed in high crime public housing while the other was given housing vouchers to move to lower-disorder neighborhoods and compared the crime rates of the two groups. If broken windows policing was true we would expect there to be less crime caused by those who moved out of public housing but there was no difference between the crime rates of the two groups. [4]

One way this policy did affect society was in discriminatory policing. With a concept as vague as disorder and with each police officer targeting what they thought constituted disorder, who was targeted and what crimes were targeted were often racially- or politically-motivated. The idea that minor disorderly crimes being a precursor to more extreme ones also may have encouraged police officers to see many more people as bad guys and encourage them to use minor crimes as a pretext for drug searches. [5]