What initially brought about communications?

This paper reports an intelligent agent equipped with two-layer finite state machines (FSMs) that can communicate by turning lighting on and off, leading to social cooperation that solves the dilemma situation, modeled by a one-shot 2 × 2 game. This communication between two gaming agents can be observed in hero- and leader-type dilemma games, where alternating reciprocity, repeating cooperation (C)-defeat (D) after D-C, is the equal pareto optimum instead of a sequence of mutual cooperation that is the equal pareto optimum for a prisoner's dilemma (PD) game.