The psychological schools are the great classical theories of psychology. Each has been highly influential; however, most psychologists hold eclectic viewpoints that combine aspects of each school.
Most influential ones
The most influential ones and its main founders are:
Behaviorism: John B. Watson
Cognitivism: Aaron T. Beck, Albert Ellis
Functionalism: William James
Humanistic/Gestalt: Max Wertheimer
Psychoanalytic school: Sigmund Freud
Systems psychology: Gregory Bateson, Felix Guattari
Complete list
The list below includes all these, and other, influential schools of thought in psychology:
Activity-oriented approach
Analytical psychology
Anti-psychiatry
Anomalistic psychology
Associationism
Behaviorism (see also radical behaviorism)
Behavioural genetics
Bioenergetics
Biological psychology
Biopsychosocial model
Cognitivism
Constructivism
Cultural-historical psychology
Depth psychology
Descriptive psychology
Developmental psychology
Ecopsychology
Ecological psychology
Ecological systems theory
Ego psychology
Environmental psychology
Evolutionary psychology
Existential psychology
Experimental analysis of behavior - the school descended from B.F. Skinner's work.
Functionalism
Gestalt psychology
Gestalt therapy
Humanistic psychology
Individual psychology
Industrial psychology
Liberation psychology
Logotherapy
Organismic psychology
Organizational psychology
Phenomenological psychology
Process psychology
Psychoanalysis
Psychohistory
Radical behaviorism - often considered a school of philosophy, not psychology.