Is Violence a Contagious Disease?In the award-winning 1957 musical play West Side Story, two street gangs—the Jets and the Sharks—wage a deadly battle for control of their New York neighborhood. A song in Act 2, “Officer Krupke,” mocks professional attempts to understand and reform the members of street gangs. “Hey, I got a social disease!” sings out one of the Jets, and the rest of the gang joins in with “Gee, Officer Krupke, we’re down on our knees, ’cause no one wants a fellow with a social disease.”

Now, more than half a century later, some criminal justice experts are taking a second look at the idea that the Jets (and many of the people who bought tickets for West Side Story) found so ridiculous. Not only is violence a disease: It’s contagious. Last year the Institute of Medicine (IOM) Forum on Global Violence Prevention conducted a workshop to discuss violence within the context of public health.

It’s a controversial position that has been adopted by the Obama administration, which commissioned a massive three-to-five year study of firearm violence based, in part, on the assertion that “violence, including firearm related violence, has been shown to be contagious.”

Some gun-ownership proponents are questioning whether violence really is a disease, and they’re asking whether the study, to be conducted by the Center for Disease Control (CDC) will add anything to our understanding of violent crime. In an article for the BizPac Review, Cheryl Carpenter Klimek cited a study showing that “accidental deaths from firearms accounted for less than one percent of all unintentional fatalities in 2010, and that mass shootings are a “small fraction of total firearm violence.”

Klimek added, “Almost all national survey estimates indicate that defensive gun uses by victims are at least as common as offensive uses by criminals, with estimates of annual uses ranging from about 500,000 to more than 3 million per year, in the context of about 300,000 violent crimes involving firearms in 2008.” Other criminal justice experts have noted that violent crime rates, including crimes committed with firearms, continue to drop steadily. Does the US really need to devote significant financial resources to studying a problem that’s declining?

At last April’s workshop on global violence prevention, a panel of experts argued that the study is necessary and the US needs to rethink its ideas about criminal acts and the people who commit them. If we view violence as an isolated act of madness or evil, the panel said, our responses are limited to building more mental hospitals and prisons. Taking a more complex view—including exploring the possibility that violent impulses can spread from one person to another—opens up more options for crime prevention.

One topic that concerned workshop participants was family life. Experts say that violent tendencies can be transmitted from adults to children in a variety of ways. Adults who habitually solve problems through aggression pass those behavior patterns on to the children who live with them. “Mirror neurons” in children, which should be reinforcing responsible behavior, end up instilling negative values and dangerous habits. Brain patterns called “priming” (firing off standard patterns in response to stimuli) and “mimicry” (copying adult role models) can have damaging long-term effects on impressionable children and teens.

Studies have shown that children who experience or witness violence at home are statistically more likely to engage in violence themselves later on—becoming abusive parents, engaging in domestic violence, or becoming enmeshed in an unhealthy relationship that eventually turns deadly.

Unfortunately, intimate violence programs tend to direct their resources towards the adult who has been victimized, ignoring the long-term damage to children in the dysfunctional home.

Another workshop topic focused on neighborhoods and communities that foster anti-social behavior.

In many jurisdictions, experts can identify “hot spots” where laws are routinely broken, police are hated, and criminals are admired and imitated. Gangs like the Jets and Sharks in West Side Story learn, teach, and live by rules and customs that put themselves and the entire community at risk. Some law enforcement agencies—New York City is a prime example—have found that a geographic approach to crime prevention can produce impressive results.

Other factors that can spread violence include racism, poverty, political unrest, and mental illness. Ironically, according to some experts at the workshop, prisons and juvenile facilities sometimes promote violence rather than subduing it. The risks are particularly great for young people who spend long days and nights almost exclusively in the company of teens with violent attitudes and aggressive behavior patterns.

The experts who spoke at the workshop suggested that a “contagious disease” model for crime prevention can lead to some workable strategies for promoting public safety. Workshop participants viewed a recent movie, The Interrupters, which documented a successful crime reduction program in Chicago and Baltimore. Known as the Cure Violence approach, this program enrolls ex-convicts as public health workers and trains them to intervene in areas where crime rates are high.

“Quarantine” (locking up lawbreakers) is an effective way to halt both a crime and a health epidemic—but, experts say, it should not be the only approach. “Interruption” (substituting new attitudes and behaviors for antisocial tendencies), education, treatment, and other interventions can be effective tools against crime. For example, giving men the opportunity to get married has been shown to reduce their likelihood of joining terrorist cells. And in some Third World countries, microloans to women have dramatically reduced domestic violence: Women with money of their own are empowered for the first time to demand humane treatment from their husbands.

Gary Slutkin, M.D., of the University of Illinois at Chicago summarized the basic theme of the workshop:  “In a violence epidemic,” he said, “behavior change is the treatment.” It is an idea that the CDC will be exploring for at least three years in the hope of discovering new approaches to the problem of violent crime.

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Jean Reynolds, Ph.D. is Professor Emeritus of English at Polk State College, where she taught report writing and communication skills in the criminal justice program. She is the author of seven books, including Police Talk (Pearson), co-written with the late Mary Mariani. Visit her website at for free report writing resources. Go to for a free preview of her book The Criminal Justice Report Writing Guide for Officers. Dr. Reynolds is the police report writing expert for Law Enforcement Today.