Is gun violence contagious?

November 02, 2017

Is gun violence contagious? According to new findings from the University of Pennsylvania and the University of Oxford, the answer is mostly no. Rather, this violence is a chronic issue for particular neighborhoods and requires place-specific solutions.

"It's been known for some time that gun violence, like many other forms of crime and other social problems, can be clustered within certain neighborhoods," says Charles Loeffler, the Jerry Lee Assistant Professor of Criminology in the University of Pennsylvania's School of Arts & Sciences. "So when we observe that a particular part of the city has an elevated risk, how do we understand what that phenomenon actually is?"

Loeffler and Oxford statistician Seth Flaxman, who published their findings in the Journal of Quantitative Criminology, turned to data from Washington, D.C., firearm-related 9-1-1 calls and acoustical sensors around the city that listen for and record the latitude and longitude of every shot fired.

Starting from the baseline that gun violence doesn't occur randomly, the researchers ran the numbers for two hypotheses. First, they asked whether such behavior could be an epidemic, something that spreads quickly and diffuses into the surrounding environment. One incident begets the next, such as a victim retaliating against a former perpetrator.

"The alternative hypothesis," Loeffler says, "is that you have clustering of gun violence in certain neighborhoods at certain times, but it may not actually be spreading in any real sense." The researchers call this an endemic pattern.

As an example, consider an encounter in a bar: Two individuals bump into each other. One takes offense at being accidentally shoved and pulls out or quickly gains access to a gun. The same scenario might happen during a drug deal, where one party feels slighted by another. In either case, the resulting action is not retaliation, but rather an aggressive response to a commonly reoccurring stimulus.

"It may not last more than a couple minutes and may not lead to further acts of violence," Loeffler says. "It could be self-extinguishing."

For Washington, D.C., the data were compelling.

"We found that a substantial fraction of the gun violence was better characterized as this endemic, non-random clustering rather than as an epidemic, contagious, diffusing process," he says.

Effective use of this information requires implementing problem-solving tactics with a better chance for success, place-based interventions that target features of a neighborhood rather than those aimed at individuals or groups, the researchers say. For instance, the greening of vacant lots or hotspot policing that puts resources toward watching crime clusters rather than toward a generic patrol.

Right now, the researchers don't know whether the results hold up for other locales, but say they plan to find out.

"It's possible to use the statistical test that we demonstrated here to understand the nature of these two hypotheses in different cities," Loeffler says. "The reality of D.C. may be different than the nature of gun-violence problems in Chicago or Los Angeles or Philadelphia."

University of Pennsylvania

Related Violence Articles from Brightsurf:

Combined intimate partner violence that includes sexual violence is common & more damaging
Women who experience sexual violence combined with other forms of intimate partner violence suffer greater damage to their health and are much more likely to attempt suicide, according to a study led by researchers at the University of Bristol's Centre for Academic Primary Care published in the International Journal of Epidemiology today [12 November 2020].

As farming developed, so did cooperation -- and violence
The growth of agriculture led to unprecedented cooperation in human societies, a team of researchers, has found, but it also led to a spike in violence, an insight that offers lessons for the present.

The front line of environmental violence
Environmental defenders on the front line of natural resource conflict are being killed at an alarming rate, according to a University of Queensland study.

What can trigger violence in postcolonial Africa?
Why do civil wars and coups d'├ętat occur more frequently in some sub-Saharan African countries than others.

Another victim of violence: Trust in those who mean no harm
Exposure to violence does not change the ability to learn who is likely to do harm, but it does damage the ability to place trust in 'good people,' psychologists at Yale and University of Oxford report April 26 in the journal Nature Communications

Victims of gun violence tell their stories: Everyday violence, 'feelings of hopelessness'
Invited to share their personal stories, victims of urban gun violence describe living with violence as a 'common everyday experience' and feeling abandoned by police and other societal institutions, reports a study in the November/December Journal of Trauma Nursing, official publication of the Society of Trauma Nurses.

Does more education stem political violence?
In a study released online today in Review of Educational Research, a peer-reviewed journal of the American Educational Research Association, three Norwegian researchers attempt to bring clarity to this question by undertaking the first systematic examination of quantitative research on this topic.

Teen dating violence is down, but boys still report more violence than girls
When it comes to teen dating violence, boys are more likely to report being the victim of violence -- being hit, slapped, or pushed--than girls.

Preventing murder by addressing domestic violence
Victims of domestic violence are at a high risk to be murdered -- or a victim of attempted murder -- according to a Cuyahoga County task force of criminal-justice professionals, victim advocates and researchers working to prevent domestic violence and homicides.

'Love displaces violence'
Art historian Eva-Bettina Krems on persistent motifs of peace in art from antiquity to the present day -- dove, rainbow or victory of love: artists draw on recurring motifs.

Read More: Violence News and Violence Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to