  Although ubiquitous, interactions of groups of individuals (e.g., modern
messaging applications, group meetings, or even a parliament discussion) are
not yet thoroughly studied. Frequently, single-groups are modeled as
critical-mass dynamics, which is a widespread concept used not only by
academics but also by politicians and the media. However, less explored
questions are how a collection of groups will behave and how the intersection
between these groups might change the global dynamics. Here, we formulate this
process in terms of binary state dynamics on hypergraphs. We showed that our
model has a very rich and unexpected behavior that goes beyond discontinuous
transitions. In particular, we might have multistability and intermittency as a
consequence of bimodal state distributions. By using artificial random models,
we demonstrated that this phenomenology could be associated with community
structures. Specifically, we might have multistability or intermittency by
controlling the number of bridges between two communities with different
densities. The introduction of bridges destroys multistability but creates an
intermittent behavior. Furthermore, we provide an analytical formulation
showing that the observed pattern for the order parameter and susceptibility
are compatible with hybrid phase transitions. Our findings open new paths for
research, ranging from physics, on the formal calculation of quantities of
interest, to social sciences, where new experiments can be designed.
