Sensing Distress Following a Terrorist Event.

Terrorism aims to cause the psychological instability in the targeted population. Social psychological research through traditional methods, like surveys or interviews, have provided insights for understanding the psychological effects of such traumatic events. However, these studies are costly and usually are reported with a significant delay after the events. With the allure of social media, we are provided with a unique opportunity to gather timely psychological signals from publicly available Twitter data. In this study, we collected more than 4 million tweets from 16 K Paris users. We present our analysis of the immediate emotional response as well as the subsequent recovery process following the Paris attacks. Our analysis shows that, immediately after the attacks, a greater level of anxiety was associated with locations closer to the attack site. Users’ emotional shift gradually returned to the pre-impact status over days to weeks, while the emotional trajectories vary with the degrees of users’ social interactions. The analysis further reveals a significant impact of media exposure on the recovery process. This study provides both theoretical and practical implications for understanding users’ emotional vulnerability and resilience concerning mass violence events.