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: Watson Cognitivism: Aaron T. Beck, Albert Ellis Functionalism: William James Humanistic/Gestalt: Carl Rogers 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 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. Psychology of self Social psychology (sociocultural psychology) Strength-based practice Structuralism Systems psychology Transactional analysis Transpersonal psychology See also History of psychology Schools, list of