Psychology (from Greek: ψυχή, psukhē, "spirit, soul"; and λόγος, logos, "knowledge") is an academic / applied discipline involving the scientific study of mental processes and behavior of humans and animals. Psychologists study such phenomena as perception, cognition, emotion, personality, behavior, and interpersonal relationships. Psychology also refers to the application of such knowledge to various spheres of human activity, including problems of individuals' daily lives and the treatment of mental health problems.
Psychology is separate from social sciences (e.g., anthropology, economics, political science, and sociology) due to its focus on experimentation at the scale of the individual, as opposed to groups or institutions. Historically, psychology differed from biology and neuroscience in that it was primarily concerned with mind rather than brain, a philosophy of mind known as dualism. Modern psychological science incorporates physiological and neurological processes into its conceptions of perception, cognition, behavior, and mental disorders.