Congratulations to Joseph Harrison


Congratulations to Joseph Harrison, who successfully defended his CSS doctoral dissertation entitled “A General Social Agent-Based Model of Opinion Dynamics With Applications To Stem Education And Radicalization.” Below is the abstract of his dissertation:

“Many aspects of our society are affected by how opinions change and ideology spreads (e.g., interest in STEM and political radicalization), but the underlying processes are not well understood. Previous attempts at modeling these phenomena have suffered from a lack of empirical data and/or insufficient grounding in social-psychological theory. Moreover, the field of opinion dynamics would benefit from a broader view of the discipline that captures the commonalities between different domains. This dissertation presents a general framework for agent-based modeling (ABM) of opinion dynamics called the meta-model and demonstrates it using ABMs in two significantly different domains: interest in the STEM fields (science, technology, engineering, and mathematics), and political radicalization resulting from personal grievance. Both models are novel within opinion dynamics in that they update agent opinions using rules designed in conjunction with subject-matter experts, and because they make use of domain-specific data. They each make substantial contributions in their respective areas of study. The first model pertains to adolescents’ interest in the STEM fields and utilizes rich longitudinal data gathered annually over 3 years. The model is calibrated using evolutionary computation, validated using subsequent surveys, and used to explore potential intervention strategies. Of those evaluated, knowledge brokering and increasing friend co-participation are shown to be demonstrably promising. The second domain, political radicalization, is explored using an ABM based on a psychological theory of radicalization grounded in the Significance Quest (SQ) theory of Kruglanski et al. (2009, 2013, 2014) and the multi-path theory of Cioffi-Revilla (2010). The model is calibrated using data from potential jihadists in Morocco, and used to explore network effects of the psychological (i.e., individual-level) radicalization processes. It shows that the psychological processes do indeed increase the number of extremists on the group level. The model shows that when traumatic events are relatively rare, exposure to diverse opinions can reduce/prevent radicalization.”


Joey’s committee members were Drs. Claudio Cioffi, Ken de Jong, Matthew Hendrey and Arie Kruglanski.