Radicalization is defined as the process by which individuals adopt extremist views, including a belief in and commitment to engaging in violence to achieve political or religious goals (Kruglanski et al., 2014). This complex transformation involves a confluence of social and psychological factors, guiding individuals down a path where violence is perceived as a legitimate course of action. According to a meta-analysis by Wolfowicz et al. (2021), which compared 37 risk factors, Ideological Obsession (IO) emerged as one of the strongest predictors of support for political violence. According to Bélanger (2021), IO is characterized by an overpowering and uncontrollable engagement with an ideology that dominates an individual's priorities and actions, influencing their propensity to Support Political Violence (SPV). Investigating the psychological mechanisms through which IO fuels SPV presents an exciting frontier in the study of radicalization, offering the potential to reveal deeper insights into the complex dynamics of this transformative process. A key factor potentially mediating the connection between IO and SPV is exposure to radical content. Indeed, researchers such as Moghaddam (2005) and Wiktorowicz (2004) have underscored the critical role played by exposure to radical content, defined as material or people that promote extremist ideologies, glorifies violence, and disseminates terrorist propaganda. This exposure is deemed a crucial component in the ideological transformation of susceptible individuals. Such a viewpoint is widely recognized across various theoretical frameworks, demonstrating a consensus among scholars (e.g., Horgan, 2008; Kruglanski et al., 2019; Sageman, 2011) regarding the significant impact that exposure to radical content has in steering individuals toward SPV. Despite this consensus, the connection between exposure to radical content and SPV remains unclear. Studies by Kenyon et al. (2022) and Pauwels & Hardyns (2018) indicate a potential link, yet a systematic review by Hassan (2018) uncovered numerous methodological challenges that make this relationship difficult to clearly establish. Issues such as 1) small sample sizes and 2) geographical biases, with a focus predominantly on participants from Western cultures, especially those in Europe and North America, restrict the generalizability of research outcomes. Additionally, there's a lack of 3) research on precursors to exposure, such as motivational factors (e.g., IO), and 4) longitudinal studies, essential for understanding radicalization as a process and the long-term effects of exposure to radical content. Compounding these issues is 5) the failure to distinguish between types of exposure (active vs. passive, online vs. offline), limiting insights into which of these four forms of exposure most significantly impact SPV. On the latter issue, Clemmow et al. (2022) introduced the “Expo-12” scale, an innovative instrument that distinguishes between the four types of exposure, thereby offering a nuanced measurement of exposure to radical content. These categories include 1) Active Seeking, where individuals intentionally search for and engage with extremist materials; 2) Active Action, which involves interactions with known extremists or participation in potentially violent protests; 3) Passive Online, referring to unintentional encounters with radical content on the internet; and 4) Passive Offline, denoting accidental exposure to such content in the physical world. This scale is a significant step forward in addressing the methodological limitations of previous research by providing a tool to examine the varied ways individuals encounter radical content. However, despite its validation, the Expo-12 scale is relatively new and has yet to be utilized in empirical studies. Consequently, at this juncture, we find ourselves in anticipation of empirical work to address several critical questions. This involves identifying the psychological factors that make individuals susceptible to being exposed to radical content and establishing which form of exposure to such content most reliably forecasts SPV. Building on the methodological advancements of the Expo-12 scale, we have conducted preliminary studies examining the relationship between IO and SPV, with a particular focus on the mediating role of different types of exposure to radical content. Our preliminary studies involved 950 Americans across four distinct ideological groups—Democrats (N = 264), Republicans (N = 254), environmentalists (N = 270), and Muslims (N = 162). In our analysis, we examined the four types of exposure to radical content: Passive Online, Passive Offline, Active Seeking, and Active Action. Among these, only Active Action mediated the link between IO and SPV, emerging as the sole robust predictor among the exposure types. Expanding upon these insights, our subsequent longitudinal study, which took place over 90 days, focused on far-right Americans (N = 153) to examine how the relationship between IO and SPV evolves over time. Results from Latent Growth Curve Analysis indicated that rising levels of IO over time were associated with increased Active Actions, leading to higher levels of SPV. Overall, these preliminary results show that Active Action mediates the relationship between IO and SPV. Our proposed study aims to build upon our preliminary research by replicating our longitudinal study conducted among far-right Americans, this time focusing on Muslims in Egypt. Egypt offers a compelling context due to its significant geopolitical role, diverse population, and rich historical context. Notably, Egypt is severely impacted by terrorist activity, as highlighted by the Global Terrorism Index (Institute for Economics & Peace, 2024), making it an ideal location for investigating radicalization processes. By extending our research into the religious (vs. political) domain, we seek to empirical examine the radicalization process in a non-Western context to enhance the reliability and generalizability of our findings. The intellectual merit of our project is underscored by the comprehensive methodology proposed for our longitudinal study, which aims to address five key limitations previously identified in the field (Hassan et al., 2018). Specifically, by conducting a well-powered study, our research addresses the critical issue of 1) small sample sizes that have limited the robustness of past findings. Furthermore, by including participants from Egypt, our study seeks to 2) mitigate cultural biases and deepen our comprehension of the dynamics of radicalization within a non-Western cultural context, thereby increasing the generalizability of the findings. Moreover, our investigation 3) delves into the antecedents of exposure to radical content, examining the role of motivational factors (i.e., IO), a topic that has been underexamined. Furthermore, our study incorporates 4) longitudinal assessments, which are essential for revealing the evolving connection between individual characteristics and their inclination toward radicalization. These assessments also enable us to examine the enduring impacts of exposure to radical content and the sequence of factors contributing to radicalization over time. Finally, 5) by distinguishing between various modes of exposure to radical content—be it active or passive, online or offline— we aim to discern their unique influences on SPV, marking a new exploration into this domain. Overall, through this endeavor, we seek to advance the theory of ideological obsession (Bélanger, 2021), offering novel insights and laying the foundation for future research to explore fruitful avenues. The impact of our research on radicalization extends across several domains, enhancing scholarly understanding, informing prevention and intervention strategies, promoting cultural sensitivity and global relevance, and contributing theoretical advancements. By addressing key limitations of prior research, our study advances the scholarly comprehension of radicalization processes through robust methodologies and comprehensive analyses, offering nuanced insights into its antecedents, trajectories, and consequences. These findings are poised to enrich the theory of ideological obsession (Bélanger, 2021), deepen empirical knowledge, and stimulate further inquiry in the field. In terms of practical applications, the insights gained from our study have direct implications for the development of more effective prevention and intervention strategies against radicalization. Identifying factors that predispose individuals to radical content, such as motivational factors (IO), enables the creation of targeted interventions designed to mitigate risks at an early stage. Our longitudinal perspective further aids in understanding the pathways of radicalization, guiding the design of intervention programs that are both sustainable and adaptive to individuals’ changing needs. This exploration not only deepens our understanding of radicalization processes but also enriches broader discussions on the psychology of ideological obsession and its impact on individual well-being and societal cohesion. Lastly, understanding which type of exposure to radical content is most strongly related to SPV may be crucial for devising targeted interventions that can effectively counter radical narratives across diverse channels.