This paper shows that being ''rational'' is not crucial for rational opportunistic political business cycle theory. Partisan and independent central banks initiate a political business cycle even if voters and central banks adapt to positive rewards. I consider a central bank that is independent but has party preferences. Voters prefer competence, but do not know the government's competence. Therefore, the central bank signals competence through an expansive monetary policy. The approach used is a simulation of artificial adaptive agents in an evolutionary programming setup. In contrast to a model with complete rationality, the convergence of the evolutionary path is not unique in the simulation. Political, non-political and non-equilibria (in a game theoretical sense) coexist. Coordination occurs frequently.