Social media posts may signal whether a protest will become violent

A USC-led study of violent protest has found that moral rhetoric on Twitter may signal whether a protest will turn violent. The researchers also found that people are more likely to endorse violence when they moralize the issue that they are protesting -- and when they believe that others in their social network moralize that issue, too. "Extreme movements can emerge through social networks," said the study's corresponding author, Morteza Dehghani, a researcher at the Brain and Creativity Institute at USC. "We have seen several examples in recent years, such as the protests in Baltimore and Charlottesville, where people's perceptions are influenced by the activity in their social networks. People identify others who share their beliefs and interpret this as consensus. In these studies, we show that this can have potentially dangerous consequences." Utilizing a deep neural network -- an advanced machine learning technique -- to detect moralized language, the scientists analyzed 18 million tweets posted during the 2015 Baltimore protests for Gray, 25, who died as police took him to jail. Then, they investigated the association between moral tweets and arrest rates, a proxy for violence. This analysis showed that the number of hourly arrests made during the protests was associated with the number of moralized tweets posted in previous hours. In fact, tweets containing moral rhetoric nearly doubled on days when clashes among protesters and police became violent. The study was published on May 23 in Nature Human Behavior. Social media as a barometer for activism Social media sites such as Twitter have become a significant platform for activism and a source for data on human behavior, which is why scientists utilize them for research. Recent examples of movements tied to social media include the #marchforourlives effort to seek gun control, the #metoo movement against sexual assault and harassment, and #blacklivesmatter, a campaign against systematic racism which began in 2014 after the police-involved shooting death of Michael Brown, 19, in Ferguson, Mo. A more violent example is the Arab Spring revolution, which began in Tunisia in late 2010, and set off protests in many other countries, including Egypt and Libya, that forced changes in their leadership. In Syria, clashes escalated into a war that has killed hundreds of thousands of people and displaced a multitude of refugees.