CIVICA Research Seminar - Iacopo Iacopini

The role of higher-order interactions in the dynamics of social contagion and norm change

Abstract:

Dynamical processes that emulate human behavior have been the focus of many studies, where social relationships and interactions are typically considered as an underlying structure. As shown recently in various contexts, it is moreover important to take into account the fact that individuals do not interact only in pairs but also in larger groups. Social interactions are indeed a natural testing ground for higher-order approaches. In this talk, I will discuss the effects of considering group interactions on the dynamics of social systems. In particular, I will generalize two models of social contagion and norm evolution, initially introduced and studied on graphs, and now extended as dynamical processes on hypergraphs. Leveraging real-world interaction data and analytical insights, I will show the emergence of novel phenomena such as discontinuous transitions and critical mass effects induced by higher-order interactions. After allowing for the presence of a committed minority, I will show that the ability of committed individuals to overturn an existing norm is non-monotonic with the number of participants in higher-order interactions. These results provide theoretical support to the observation that extremely small minorities can overcome the opinion of the corresponding large majority of the population. Finally, I will propose a measure of hyper-coreness to characterize the centrality of nodes in hypergraphs, and show how different seeding strategies can play a crucial role in dynamical processes driven by group interactions. Overall, the findings confirm the relevance of exploring network representations beyond pairwise interactions when modeling social phenomena. 

Bio:

Speaker's bio: https://iaciac.github.io/

CIVICA Research brings together researchers from eight leading European universities in the social sciences to contribute knowledge and solutions to the world’s most pressing challenges. The project aims to strengthen the research & innovation pillar of CIVICA, the European University alliance. CIVICA Research is co-funded by the EU’s Horizon 2020 research and innovation program