This book combines theoretical and empirical research across various academic disciplines including economics, psychology, neuroscience, philosophy, and political science to describe why individuals adopt political ideologies and how this choice can potentially exacerbate conflict and violence. Ideology is particularly important to conflict. Data on intra- and international conflict shows that the number of ideologically driven conflicts has increased tremendously in recent decades. Although some researchers started to investigate this link extensively, they struggle to find holistic explanations. The book illustrates that ideologies are not only capable of shaping conflictual behavior or mobilizing political actors, but also of addressing human needs, desires, and preferences. Hence, the authors compile valuable insights from various academic disciplines to explain how individuals adopt ideologies that match their underlying needs and preferences; that ideologies have the capacity to reconcile deprived psychological human needs; and that radical groups and organizations use ideologies to recruit individuals and pursue their objectives. Real-life cases are included to better understand these relationships and to apply the theoretical background to real-world situations.