Title: Determinants of public cooperation in multiplex networks,
Abstract: Synergies between evolutionary game theory and statistical physics have
significantly improved our understanding of public cooperation in structured
populations. Multiplex networks, in particular, provide the theoretical
framework within network science that allows us to mathematically describe the
rich structure of interactions characterizing human societies. While research
has shown that multiplex networks may enhance the resilience of cooperation,
the interplay between the overlap in the structure of the layers and the
control parameters of the corresponding games has not yet been investigated.
With this aim, we consider here the public goods game on a multiplex network,
and we unveil the role of the number of layers and the overlap of links, as
well as the impact of different synergy factors in different layers, on the
onset of cooperation. We show that enhanced public cooperation emerges only
when a significant edge overlap is combined with at least one layer being able
to sustain some cooperation by means of a sufficiently high synergy factor. In
the absence of either of these conditions, the evolution of cooperation in
multiplex networks is determined by the bounds of traditional network
reciprocity with no enhanced resilience. These results caution against overly
optimistic predictions that the presence of multiple social domains may in
itself promote cooperation, and they help us better understand the complexity
behind prosocial behavior in layered social systems.