The environmental factors that contribute to crime have been immensely popular ever since The Tipping Point highlighted the so called broken windows theory popularised by former mayor of New York Rudolph Guiliani. The theory states that the environment we find ourselves in has a hidden, yet powerful influence over our behaviours. The broken windows of the theories name, along with other seemingly minor societal dysfunctions, can be enough to normalise criminal behaviour.
A new study from Yale’s Department of Sociology has looked at the environmental influences on crime in a more base way by looking at the role our social networks play. The study looks in particular at gun violence, which it likens to a blood-borne pathogen. It reveals that crime, like a disease, tends to follow certain distinct patterns, with people in the same social network likely to mimic the behaviours of their peers.
“Risk factors like race and poverty are not the predictors they have been assumed to be,” said the researchers, “It’s who you hang out with that gets you into trouble. It’s tragic, but not random.”
The researchers studied police records in Chicago from 2006 to 2011, looking in particular at a six square mile chunk of the city that had the highest homicide rates. They discovered that just 6% of the population were responsible for over 70% of the murders, with nearly all of those people already having had some contact with either the criminal or public health systems.
What’s more, those in the 6% group were 900% more likely to become victims of gun homicide themselves. They were therefore both a higher risk of being both perpetrator and victim of gun crime.
The Chicago Police Department have started to analyze data such as this to identify the area’s top 20 highest risk individuals. The police force can then visit these people, explaining to them how their social network had placed them on the high risk list, and told them how important their lives were, before offering help to keep them out of trouble. “The CPD is using this as a way to reach out to people, rather than just make arrests,” the researchers say.
The initiative is in its early days so it isn’t yet clear how effective it has been in reducing gun crime, but the approach is being closely monitored by other cities that want to reduce their own gun crime.
It’s a nice example of how big data and social networks can be used to identify trends that make our actions more effective.