Overall behaviouralism now has five stages of evolution:
(1) Individualistic pre-war behaviouralism (1900-1930):
It was contributed by Graham Wallas. (Human Nature in Politics, 1908), Arthur F. Bentley (The Process of Government, 1908), Walter Lippman (Public Opinion, 1922), Charles E. Merriam (New Aspects of Politics, 1925), David B. Truman (The Governmental Process, 1950), Lasswell, Key, Simon, Almond etc. of the Chicago School and European contributions from Marx, Durkheim, Freud, Pareto, Mosca, Michels, Weber and others. More attention was paid to quantitative aspects of politics.
(2) Collective collaboration after the World War II (1930-1950):
Massive efforts were made by philanthropic institutions, academic associations, university departments, and the governments of the United States. American Political Science Association, Social Science Research Council, Carnegie, Ford and Rockfeller Foundations came forward to forge it ahead. Journals like American Political Science Review, Public Opinion, World Politics, and Comparative Politics etc. regularly appeared. Scholars like David Easton, Deutsch, Heinz Eulau etc are thinkers of this phase. Behaviouralism appeared with its own methodology in both substantive and non-substantive areas.
(3) Era of experts and specialists (1950-60):
During this era, scholars finally separated themselves from behaviourism of E.L. Thondike (1878-1949), K.S. Lashley (1890-1959), Watson (1884-1952), B.F. Skinner (1904-1990) etc. and using the terminology of I. Pavlov. They evolved multimethodologism, new areas of specialisation, and micro and macro behavioural theories. Behaviouralists gained ascendancy in almost all universities and major academic institutions.
(4) Pure and applied behaviouralism (1960-70):
Behaviouralism appeared in two forms:
(a) Theoretical, and
Theoretical behaviouralists are also known as ‘pure’ behaviourlists. Knowledge for the sake of knowledge was their goal. They devoted themselves to ‘basic’ or ‘fundamental’ research which contributes to empirical political theory as well as formulation of scientific tools and techniques. They conducted studies toward ‘Why it so happens?’ e.g., violence, casteism etc. They were interested in conceptualising basic processes of societal operations.
During the course of conducting research they developed language or concepts of their own which sharply limits the number of audience. Positive behaviouralists criticise theoretical behaviouralism, and give priority to mathematical techniques, multi-variate analysis, model-making etc.
Research into immediate and urgent problems of a polity makes them ‘applied’ behaviouralists. They take up empirical studies of governments, associations, institutions, groups etc. and seek help from other disciplines. Sometimes they appear as social reformers and have wider audience.
They feel no need to generalise. Both varieties of behaviouralists criticise each other but can mix up in any research venture. In this process, they tend to go from outward human behaviour to ecology to bio-politics to psychology to genetics. In this process, sometimes, Norman Jacobson observes the very existence of Political Science evaporates.
(5) Post-behaviouralism and after (1970-2006):
Post-behaviouralism appeared as a result of dissatisfaction with the nature, achievements and limitations of behaviouralism. David Easton himself (1969), along with other classicists, and all types of groups, criticised it. It became an end in itself, and lost touch with social reality and polity. It could neither produce any ‘science of politics’ nor any empirical theory.
Having discarded values as their central concern, they alienated society and the people who were more interested in the solution of immediate crises and problems, and reform social structures. At first, behaviouralists tried to remove misunderstanding and rebut criticism against them. Dissatisfied with their defensive explanation, another revolution emerged in the same direction.