(Hard)Wired for Terror is divided into two parts. In the first part, (the ‘Roots’ ) we provide a historical, semantic analysis of the concepts of radicalism, extremism and terrorism, and how they are interconnected. Furthermore, a comprehensive overview is presented of the state of the art in which the current radicalization and terrorism research is rooted. We challenge insights from individual-psychological and collective-sociological research and bind them together on a social-communicative dimension. By means of a theoretical blend of Social Movement Theory, Mediatization, and Socio-Epidemiology, we propose a new cyclic model of mediatized terrorism and radicalization. In the second part (the ‘Routes’ ), we present the results of five original empirical studies. Both message-centered and audience-centered analyses were conducted. On the basis of a detailed content analysis, we uncover the moral psychological and theological underpinnings of the ISIS’s worldview. Additionally, survey data of Belgian young adults reveal the ‘effects’ of different forms of Salafi-Jihadist communication artefacts (from beheading videos to terrorist attacks). Ultimately, the dissertation suggests a few policy recommendations with the aim to prevent radicalization and terrorism.