  Motivated by the literature on opinion dynamics and evolutionary game theory,
we propose a novel mathematical framework to model the intertwined coevolution
of opinions and decision-making in a complex social system. In the proposed
framework, the members of a social community update their opinions and revise
their actions as they learn of others' opinions shared on a communication
channel, and observe of others' actions through an influence channel; these
interactions determine a two-layer network structure. We offer an application
of the proposed framework by tailoring it to study the adoption of a novel
social norm, demonstrating that the model is able to capture the emergence of
several real-world collective phenomena such as paradigm shifts and unpopular
norms. Through the establishment of analytical conditions and Monte Carlo
numerical simulations, we shed light on the role of the coupling between
opinion dynamics and decision-making, and of the network structure, in shaping
the emergence of complex collective behavior in social systems.
