Krapivsky, P. L. and S. Redner
We investigate majority rule dynamics in a population with two classes of people, each with two opinion states +/- 1, and with tunable interactions between people in different classes. In an update, a randomly selected group adopts the majority opinion if all group members belong to the same class; if not, majority rule is applied with rate epsilon. Consensus is achieved in a time that scales logarithmically with population size if epsilon >= epsilon(c) = 1 9. For epsilon < epsilon(c), the population can get trapped in a polarized state, with one class preferring the +1 state and the other preferring -1. The time to escape this polarized state and reach consensus scales exponentially with population size.