  From families to nations, what binds individuals in social groups is the
degree to which they share beliefs, norms, and memories. While local clusters
of communicating individuals can sustain shared memories and norms, communities
characterized by isolated cliques are susceptible to information fragmentation
and polarization dynamics. We employ experimental manipulations in lab-created
communities to investigate how the temporal dynamics of conversational
interactions can shape the formation of collective memories. We show that when
individuals that bridge cliques (i.e., weak ties) communicate early on in a
series of networked interactions, the community reaches higher mnemonic
convergence compared to when individuals first interact within cliques (i.e.,
strong ties). This, we find, is due to the tradeoffs between information
diversity and accumulated overlap over time. By using data calibrated models,
we extend these findings to a larger and more complex network structure. Our
approach offers a framework to analyze and design interventions in
communication networks that optimize shared remembering and diminish the
likelihood of information bubbles and polarization.
