  A social system is considered whose agents choose between several
alternatives of possible actions. The system is described by the fractions of
agents preferring the corresponding alternatives. The agents interact with each
other by exchanging information on their choices. Each alternative is
characterized by three attributes: utility, attractiveness, and replication.
The agents are heterogeneous having different initial conditions and different
types of memory, which can be long-term or short-term. The agent interactions,
generally, can depend on the distance between the agents, varying from
short-range to long-range interactions. The emphasis in the paper is on
long-range interactions. In a mixed society consisting of agents with both
long-term and short-term memory, there appears the effect of spontaneous
excitation of preference waves, when the fractions of agents preferring this or
that alternative suddenly start strongly oscillating, either periodically or
chaotically. Since the considered society forms a closed system, without any
external influence, the arising waves are internally self-excited by the
society.
