Psychology (Greek: Ψυχολογία, lit. "study of the mind", from lang: ψυχή psykhē "breath, spirit, soul"; and lang: -λογία, -logia "study of") is an academic and applied discipline involving the scientific study of human mental functions and behavior. Occasionally, in addition or opposition to employing the scientific method, it also relies on symbolic interpretation and critical analysis, although these traditions have tended to be less pronounced than in other social sciences such as sociology. Psychologists study such phenomena as perception, cognition, emotion, personality, behavior and interpersonal relationships. Some, especially depth psychologists, also study the unconscious mind.

Psychological knowledge is applied to various spheres of human activity, including issues related to everyday life—such as family, education and employment—and to the treatment of mental health problems. Psychologists attempt to understand the role of mental functions in individual and social behavior, while also exploring the underlying physiological and neurological processes. Psychology includes many sub-fields of study and applications concerned with such areas as human development, sports, health, industry, media and law. Psychology incorporates research from the natural sciences, social sciences and humanities. A person who studies or practices psychology is called a psychologist.

History

main: History of psychology

Philosophical and scientific roots

The study of psychology in philosophical context dates back to the ancient civilizations of Egypt, Greece, China and India. Psychology began adopting a more clinical and experimental approach under medieval Muslim psychologists and physicians, who built psychiatric hospitals for such purposes.

In 1802, French physiologist Pierre Cabanis helped to pioneer biological psychology with his essay Rapports du physique et du moral de l'homme (On the relations between the physical and moral aspects of man). Cabanis interpreted the mind in light of his previous studies of biology,arguing that sensibility and soul are properties of the nervous system.

Though the use of psychological experimentation dates back to Alhazen's Book of Optics in 1021,Omar Khaleefa (Summer 1999). "Who Is the Founder of Psychophysics and Experimental Psychology?", American Journal of Islamic Social Sciences 16 (2).Bradley Steffens (2006). Ibn al-Haytham: First Scientist, Chapter 5. Morgan Reynolds Publishing. ISBN 1599350246. psychology as an independent experimental field of study began in 1879, when Wilhelm Wundt founded the first laboratory dedicated exclusively to psychological research at Leipzig University in Germany, for which Wundt is known as the "father of psychology". The year 1879 is thus sometimes regarded as the "birthdate" of psychology. The American philosopher William James published his seminal book, Principles of Psychology in 1890, laying the foundations for many of the questions that psychologists would focus on for years to come. Other important early contributors to the field include Hermann Ebbinghaus (1850–1909), a pioneer in the experimental study of memory at the University of Berlin; and the Russian physiologist Ivan Pavlov (1849-1936) who investigated the learning process now referred to as classical conditioning.