Consensus and Polarization in Competing Complex Contagion Processes

Abstract

In many situations, the rate of adoption of new information depends on reinforcement from multiple sources in a way that cannot be described by simple contagion processes. In such cases, contagion is said to be complex. This has been found in the diffusion of human behaviors, innovations, and knowledge. Based on that evidence, we propose a new model considering multiple, potentially asymmetric, and competing contagion processes and analyze its respective population-wide complex contagion dynamics. We show that the model spans a dynamical space in which the population exhibits patterns of polarization, consensus, and dominance, a richer dynamical environment that contrasts with single simple contagion processes. We find that these patterns are present for different population structures. We show that structured interactions increase the range of the dominance regime by reducing that of polarization. Finally, we show that external agents designing seeding strategies, to optimize social influence, can dramatically change the coordination threshold for opinion dominance, while being rather ineffective in the remaining dynamical regions.