Propagation of radical ideas in societies with memory: Competition between radical strength and social cohesion

Based on a dynamical model employing fractional derivatives we discuss the evolution of radical groups in a society with memory in terms of the active proselytism of radical groups and the level of cohesion in social networks. We find the conditions that determine that the radical group either disappears or, on the contrary, achieves a permanent significant expression. We also discuss the possible intervention strategies on the susceptible population and show the conditions that lead to the disappearance of radical groups. Regarding the application of this policy, we find that the higher the level of memory, the maximum proportion of radicals decreases, but those groups manage to maintain their presence in society during a larger period of time. (c) 2021 Elsevier Ltd. All rights reserved.