  Diffusion processes in a social system are governed by external triggers and
internal excitations via interactions between individuals over social networks.
Underlying mechanisms are crucial to understand emergent phenomena in the real
world and accordingly establish effective strategies. However, it is
challenging to reveal the dynamics of a target diffusion process due to
invisible causality between events and their time-evolving intensity. In this
study, we propose the Latent Influence Point Process model (LIPP) by
incorporating external heterogeneity and internal dynamics of meta-populations
based on human mobility. Our proposed model quantifies the reflexivity of a
social system, which is the level of feedback on event occurrences by its
internal dynamics. As an exemplary case study, we investigate dengue outbreaks
in Queensland, Australia during the last 15 years. We find that abrupt and
steady growth of disease outbreaks relate to exogenous and endogenous
influences respectively. Similar diffusion trends between regions reflect
synchronous reflexivity of a regional social system, likely driven by human
mobility.
