Introduction In previous chapters, we have seen that radicalization and terrorism can be influenced by a variety of social factors including prejudice and deprivation, as well as by aspects related to culture and the general social climate: cultural values, economic circumstances and so on. These do not provide a full picture of all the relevant determinants, however. No two people are the same, and considering their individual differences may take us a step closer to understanding why some radicalize and others do not. As Allport (1954/1979) already stated in relation to prejudice, radicalization and terrorism have multiple causes. In this chapter, we discuss how personality and demographic characteristics – gender and age, for instance – relate to threats and to radicalization and terrorism. In the process, we will once again look at certain explanatory mechanisms that have already been introduced in previous chapters, such as perceived threat and uncertainty.