Do you know how Design, Criminology, Sociology and Economy can cooperate to address the social phenomenon described by the Broken Windows Theory?

1. Design: Fundamental Principles of Interaction

Researching on User Experience, I came across a book by Don Norman, “Design of Everyday Things”. Norman explains that all artificial things are designed, including not only physical things, but also services, rules, procedures or organizational structures. Given that things are designed for people, design should focus on both things and people and understand how they interact with each other.

On this basis, to design functional, easy, intuitive and delightful thing-person interactions, Don Norman proposes 6 fundamental principles. The first two, affordances and signifiers, caught my attention:

  • An Affordance is the relationship between the properties of an object and the abilities of a person that determine how the object can be used. Thus, for example, glass door affords transparency (property) yet, in turn, it also prevents the passage of people. This blockage (another property) can be considered as an anti-affordance.
  • Often, affordances and anti-afordances are perceived and understood by themselves, as the transparency of the glass (see through) or a handle (open), but sometimes they aren’t so obvious (how many people have bumped into a glass door). In these cases, design requires signifiers, perceivable indicators that communicate what actions can be done, how and where (a push sign, for example).


At this point, the author explains that some accidental affordances can become signifiers, giving the real example of a wall of about four feet tall whose evident anti-affordance was preventing people from falling down the stair shaft. The top of the wall, however, was flat, affording a surface for supporting objects. And, indeed, this is what happened. Someone placed on the top of the wall an empty drink container. This container, in turn, became a signifier, encouraging more people to leave there cans and other containers.

This example brought to mind the university toilets doors with graffiti, the paths through the gardens or the illegal dumping grounds. And it also made me think of the Broken Windows Theory.

2. Criminology: The Broken Windows Theory

In 1969, Philip Zimbardo, a Stanford psychologist, conducted an experiment. He parked a car without license plates and with its hood up on a street in the Bronx and another in Palo Alto, California. The car in the Bronx was attacked within 10 minutes of being there. The car in Palo Alto, however, remained intact for a week. So, Zimbardo himself smashed a window. Soon, passersby, “primarily respectable whites”, joined in the destruction of the car.

This case would become the basis of the “Broken Windows Theory”, developed in 1982 by the criminologists James Q. Wilson and George L. Kelling. According to this theory, supported by several experiments, if a window is broken and  left unrepaired, people will conclude that the people of that community doesn’t care and no one is in charge, so more windows will be broken soon. These windows, in turn, will reinforce the message of neglect and lack of control and the degree of vandalism and crime will increase gradually to turn the place into a dangerous area for its inhabitants.

The first conclusion of this theory is that low-level anti-social behaviors can escalate and lead to more serious crimes and urban decay if they aren’t tackled at source. Without doubt, the relationship between the Broken Windows Theory and the first two principles of interaction design is evident (accidental affordance > broken window > signifier > more broken windows).


In the mid-1980, Kelling was hired by the New York City Transit Authority to manage the serious problem of vandalism in the subway. He put the Broken Windows Theory intro practice and the first actions were the graffiti cleanup and the fight against fare-beating. These and other measures contributed greatly to reduce the problem of insecurity. Rudolph Giuliani, elected as mayor of New York in 1994, also applied the theory to reduce the city crime rate.

The Broken Windows Theory has received many criticisms, but I think that in most cases these cannot be attributable to the theory itself, but to its political use. Thus, this theory has served in many cases as a “scientific basis” to justify controversial Zero Tolerance policies, sometimes criminalizing the outsiders.

First, we must remember that the first “vandals” are always the “respectable” insiders. Second, the theory exposes something obvious from the point of view of design: if people react to the environment, the solution could be found in the environment itself.

If design provides an explanation to the Broken Windows phenomenon, why not looking for a solution in design? Criminology, design and urban planning should collaborate to prevent meddling political interests.

3. Sociology: Emergent Effects

Though design provides a framework to understand why someone breaks a window, or paints graffiti on the toilet door, we cannot forget that the global phenomenon of Broken Windows is, in fact, a social phenomenon.

The vandalism escalation process is merely an emerging effect, i.e., the unintentional result of a set of intentional individual actions. The individual actions (like breaking a window or painting graffiti) take place within a system of interdependence, which often generates unintended collective phenomena (urban degradation or the destruction of toilets). The effects of these individual actions are amplified because of the interdependence of people.

The sociologist Raymond Boudon extensively explained this phenomenon in “The Logic of Social Action”. To understand these processes is necessary to analyze the structure where they take place: the system of interdependence (people and their characteristics), the context (institutional, economic and historical variables) and the outputs. In the Broken Windows process, the output (broken windows, graffiti, etc.) acts over the own system through a feedback mechanism that generates a cumulative process.

model boudon broken window

Without going into details, the analysis of emergent phenomena shows us that the Broken Windows Theory describes a complex system requiring a sociological understanding of the actors, the environment and their interdependence. Design can help eliminate accidental affordances and use appropriate signifiers, but sociology has an important role to deactivate the feedback and dissemination process that turns small individual actions into collective phenomena.

4. Economy: Governing Common Pool Resources

Finally, we cannot ignore the fact that the Broken Windows Theory, in most cases, applies to contexts of public spaces and resources, such as streets, parks, trains, stairs or public toilets, where this kind of conflict arises.

With regard to the management of common pool resources, the general idea is that without the supervision of a higher authority (state, government, leader), people are unable to manage their own shared resources without damaging them.

Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons. – Garrett Hardin

However, Elinor Ostrom, Nobel Prize Winner for Economics in 2009, showed that certain communities were able to self-manage their common pool resources, even better than other communities governed by an authority. Ostrom analyzed these success cases and compared them with cases where resources were degraded and found eight properties.

These properties, which have been subsequently slightly modified and expanded, are known as “Design Principles by Long-Enduring Common-Pool Resources”. I’m not going to explain here all the principles. I’ll just name a few, such as clearly defined resource boundaries, appropriation rules consistent with local conditions, graduated sanctions, monitoring, collective-choice arrangements or conflict resolution mechanisms.

Ostrom’s research on the management of common pool resources could be a essential tool to prevent the occurrence of the phenomenon of the Broken Windows. Despite the emphasis placed on the danger from the outsiders, this phenomenon is usually triggered by the communities themselves. They are who, in the first place, are unable to manage their common resources.

Obviously, the police is a necessary tool to control some anti-social behaviors, but responsibility cannot drop entirely on the authorities shoulders. An autonomously and sustainably managed community will be always a much healthier and economical solution.


Complex social phenomena require the cooperation of multiple disciplines in order to produce successful things-people interactions. The combination of fields such as design and sociology may offer a tool for understanding social phenomena and manage them properly. At the same time, none of them alone has the whole truth.