Theories, Systems, and Paradigms Psychology is the study of the way people think and behave. The field of psychology has a number of subdisciplines devoted to the study of the different levels and contexts of human thought and behavior that includes theories, systems, and paradigms. Theories, systems, and paradigms have had an important effect on psychology. A theory is a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena. A theory can also be explained as an abstract thought or speculation. There are many different theories of abnormality and treatment.

These approaches include the psychoanalytic, neo-Freudian, gestalt, cognitive behavior therapy, humanistic psychology, and transactional analysis. Theories have provided psychology with the way to analyze a set of facts and how they relate to one another. "Traditional studies of theory have generally focused on individual theorists, core concepts, intellectual histories, or "schools" of social thought" (Wells). Studies of individual theorists generally catalogue a brief biographical account, list basic assumptions, and present the major works of each person classified as a social theorist. Core concept approaches to theory outline a basic conceptual model and generally synthesize relevant historical and empirical research. The approach of intellectual history describes the sociocultural context of theoretical systems and the future of idea-systems on the works of subsequent theorists.

The schools of social thought approach organizes the study of theory in terms of groups of theorists who share similar assumptions and approaches to the study of human behavior. In American psychology, systems and theories historically have been very closely associated. A system of psychology may be defined as "an interpretation of data and theories with special assumption (postulates), definitions, and methodological biases" (Marx and Hillix, 1979, p. 490). The key word in this definition is the last one, "biases", because in essence a system represents a predisposition toward the selection of problems, methods, observations, and interpretations. The systems that have been most influential in American psychology are generally agreed to be structuralism, functionalism, behaviorism, Gestalt psychology, and psychoanalysis. Sets of interacting units with relationships among them form these systems.

For example, structuralism has no concrete mental process, no idea of feeling that we actually experience as part of a consciousness, is a simple process, but that all alike are made up of a number of simple processes blended together. These simple processes are called mental elements (Sahakian, 1975, p. 353). Functionalism is conceived as the psychology of mental operations in contrast to the psychology of mental elements; or, expressed otherwise, the psychology of the how and why of consciousness as distinguished from the psychology of the what of consciousness (Sahakian, 1975, p. 366). Kuhn's introduction of the paradigm concept has served as a basis for reorganizing the study of the social sciences in general and sociological theory in particular. A paradigm provides a basis for taking an inventory of existing findings in the field; for indicating contradictory, contrary and consistent results (Cullen). A paradigm in Kuhn's inclusive sense involved nearly everything necessary for doing science, all the way from a particular set of metaphysical assumptions "at the top" through commitments to apparatus and experimental procedures "at the bottom" (Marx and Hillix, 1987).

Although the importance of Kuhn's contribution to the study of the social sciences is and will probably continue to be a point of discussion and controversy, the paradigm concept along with the specification of paradigm components have served as major organizing devices for the study of theory (Wells). Theories, systems, and paradigms have had a huge impact on psychology, as we know it today. As more theories, systems, and paradigms develop, the path for American psychology will lead to an innovative future. A system of psychology may be defined as "an interpretation of data and theories with special assumptions (postulates), definitions, and methodological biases" (Marx and Hillix, 1979, p. 490).