The Role of Reinforcement on Social Dynamics

Note: Pizza served at 11:45 AM
Speaker: Sid Redner, Boston University, Physics Dept.

When: February 4, 2011 (Fri), 12:00PM to 01:00PM (add to my calendar)
Location: SCI 352
Hosted by: Ophelia Tsui

This event is part of the Biophysics/Condensed Matter Seminar Series.

Abstract:
In many models of social dynamics, some attribute is transferred by a single interaction between agents that causes an agent to change its state. What happens, however, if an agent requires multiple signals from its neighbors before changing state? The result is quite rich. We first present a simple fad propagation model in which an agent adopts the fad only after receiving K inputs to adopt from other agents. For a population size N, the time until
the fad is adopted scales as ln N for K=1, and N^{(K-1)/K} for K>1. For the voter model with K inputs needed to change state, a two-time scale approach to consensus is found. There is a manifold of initial conditions that leads the population to almost immediately reach an “apathetic” state before consensus is reached in a time that scales as ln N.