The proposed model operationally defines "counteractance" in three tenses by formulas specifying: how to identify it in fitting harmonic curves (i.e.,=k/x); how to produce it from preconditions of two measurable and opposed interactions where everyone has equal opportunity to interact; and how to predict in such situations. In four controlled experiments in series of towns an interaction in the form of the diffusion of a message was found with excellent fits to vary inversely with powers of four counteracting factors when isolated in turn, namely: the distance between interactors; the time sequence of interacting; the population size of interactors; and increments in stimulation.