Researchers with the Georgia Institute of Technology have used the Mexican drug wars to demonstrate that there is a significant link between increased violence and the growing desensitisation of social media posts.
Researchers analysed the patterns of violence in four Mexican cities, using official homicide statistics and a prominent narcotics blog, together with all Spanish-language Twitter postings.
While the number of posts by Mexican citizens experiencing violence has remained stable or increased, researchers found that negative emotions expressed in the tweets had decreased significantly.
"General psychological research has demonstrated that prolonged exposure to violence, whether directly or word of mouth or through media reports, can have lasting and detrimental impact including emotional numbness or desensitisation," said Munmun De Choudhury, who led the research team.
"Our research finds that this holds true with social media. Strong psychological markers of desensitisation followed rises of violence in the Mexican drug war."
The Mexican drug war has been going on since December 2006, whereby rival drug cartels have been involved in an ongoing armed conflict amongst themselves, as well as the Mexican military and civilian vigilante groups, in order to gain control of drug trafficking routes into the United States.
Although official records vary, it is believed that up to 100,000 people have been killed so far.
"In Mexico, Twitter has acted as a unique platform allowing affected people to express their emotions, be it their frustrations or grievances or anger, about their circumstances as well as feelings of terror," said De Choudhury.
"This not only expands the narrative of how citizens are dealing with the drug war, but our findings can also help researchers build theories about socio-psychological responses to crises."
The Georgia Tech team's paper, Narco' Emotions: Affect and Desensitisation in Social Media during the Mexican Drug War, will be presented at CHI 2014, the leading conference on human-computer interaction, in Toronto in April.