  A current paradigm in computer simulation studies of social sciences problems
by physicists is the emergence of consensus. The question is to establish when
the dynamics of a set of interacting agents that can choose among several
options (political vote, opinion, cultural features, etc.) leads to a consensus
in one of these options, or when a state with several coexisting social options
prevail. We consider here stochastic dynamic models naturally studied by
computer simulations. We will first review some basic results for the voter
model. This is a binary option stochastic model, and probably the simplest
model of collective behavior. Next we consider a model proposed by Axelrod for
the dissemination of culture. This model can be considered as a multivariable
elaboration of the voter model dynamics.
