Different behaviorists have adopted the different theories. Karl Deutach developed the ‘Quantitative Theory ‘, which says that the communications or flow of nations is vital to healthy international relations. Richard C.Synder developed the “Decision Making Approach “ in which much emphasis was given to the need of probing the minds of the decision makers. This approach held that decisions are nothing but reactions to a given situation-taking place in a certain setting. This approach was criticized on the ground that the international relations are not made of highly coutious moves and choices, which can be analyzed.
Liska propogated ‘Equilibrium Theory of international Relations and Institutions.’ According to him, the states seek to secure the best attainable position of equilibrium and this is a desirable policy for safeguarding human values. Professor Kaplan and McClelland built the system Theory that holds that a theory of international politics, normally, cannot be accepted to predict individual actions.