Extremism and Radicalisation. A Systematic Review of Empirical Evidence for Personality, Quest for Significance, Spirituality and Intolerance of Uncertainty

<title>Abstract</title> <p>Extremism and radicalisation pose significant threats to national security and socio-political stability, particularly in Western countries. Despite the extensive scientific literature addressing these phenomena from various perspectives, existing empirical research lacks cohesion due to differing theoretical models. This systematic review aims to unify recent empirical research on psychological factors associated with extremism and radicalisation, focusing on empirical studies across diverse cultural and socio-political contexts. Key findings indicate that certain personality traits—specifically, low openness to experience and high conscientiousness—may increase susceptibility to extremist beliefs. Additionally, quest for significance seems to stand out as a powerful motivator for radicalisation. Spirituality seems to play a complex role: it may mitigate or, conversely, amplify extremist tendencies, depending on interpretative frameworks and group dynamics. Intolerance of uncertainty is another critical factor, as individuals with low tolerance for ambiguity may be drawn to extremist ideologies that offer rigid, black-and-white perspectives. This review emphasises the importance of a comprehensive understanding of these psychological variables, which, altogether, suggest that both individual traits and contextual factors contribute to radicalisation pathways and extremism. The findings highlight opportunities for targeted interventions, suggesting directions for future research to develop more effective strategies for preventing radicalisation in clinical and community environments.</p>