The field of psychology is comprised of at least seven schools of thought. Each of these schools of thought views the field of psychology in different ways. Nearly 140 years after its formal founding, academic psychology continues to be a collection of disparate theoretical schools without a unified approach or definition of the field. Most psychologists and psychology textbook authors identify themselves as cognitive psychologists. The definition of psychology found in most textbooks reflects the cognitive orientation of the authors.

Cognitive Psychology

Since the 1970s, most psychologists identify themselves as cognitive psychologists. Cognitive psychologists view the brain as a computer. The cognitive school of thought privileges experimental methodology and the scientific method. Cognitive psychology is both a therapeutic psychology and a research discipline.

A common definition of psychology, as proposed by cognitive psychologists, is the scientific study of behavior and mental processes.

Biological Psychology

Biological psychology focuses on the nervous, endocrine and genetic communication systems. The three philosophical foundations of biological psychology are materialism, mechanism and reductionism.

Materialism is the theoretical position that all psychic or mental phenomena are caused by material substance, such as chemicals, neural cell or genes.

Mechanism is the belief that the brain works in a mechanized, clockwork fashion, governed by laws.

Reductionism is the theoretical position that holds that material elements can be understood through increased dissection.

A biological definition of psychology could be: the scientific study of the biological foundations of behavior and mental processes.

Evolutionary Psychology

Evolutionary psychologists attempt to understand thinking, feeling and behaving as strategies for survival and reproduction. Through environmental and social pressures, evolutionary psychologists explore the functional aspect of psychological phenomena and behavior.

Evolutionary psychology is defined as the study of the evolutionary processes that shape behavior and mental processes.

Psychodynamic Psychology

Sigmund Freud founded the new science of psychoanalysis in the 1890s. The new science included techniques to research aspects of the psyche that are not directly observable. The theoretical concept of the unconscious is at the center of psychodynamic research.

There are many schools of thought within psychoanalysis, broadly referred to as psychodynamic theories. Although some of these affiliations embrace the scientific method, most view experimental research as superficial and naive. Psychodynamic psychologists are typically therapeutic psychologists, but psychoanalytic research has become increasingly popular in media, cultural, art and literature studies.

A definition of psychodynamic psychology is: the study of the personal and collective unconscious dynamics of the psyche.

Humanist Psychology

Humanist psychologists largely reject the experimental research method and instead focus on human potential, self-actualization and social bonds. Humanist psychologists are typically therapeutic psychologists.

Humanist psychology could be defined as the holistic study of human potential, spirituality and self-actualization.

Behavioral Psychology

Behaviorism was the dominant perspective of American psychology from the early 1900s through the 1960s. The behavioral psychologists presented themselves to be hard scientists of behavior. The behaviorists researched two learning theories: associative conditioning and operant conditioning.

The definition of psychology, used by behavioral psychologists is the scientific study of behavior.


Most philosophers of science and systems of psychology view the field as a collection of different theoretical and research orientations. It is debated what the future definition of the academic discipline will be, but currently the cognitive, biological and evolutionary schools dominate academic psychology.