Psychology is the branch of knowledge concerned with the study of behavior and mental processes. Modern psychology is rooted in a variety of traditions including philosophy, medicine, and biology, and therefore covers a wide area of study and involves a great diversity of activities. It is an academic discipline with a long and productive tradition of scholarship and scientific research. It is also a profession that conducts and applies the products of research in the arena of human services. In addition, fields such as education, law, medicine, social services, management, advertising, industrial engineering, environmental design, and public administration draw upon psychological principles. Psychology examines behavior and mental processes at a variety of levels from the molecular (e.g., the role of particular chemicals in brain function) to the global (e.g., the role of cultural factors in promoting achievement motivation). Students of psychology have the opportunity to learn how people sense and perceive their environment, process and remember information, experience emotions, and cope with the difficulties they encounter. In addition, they learn how all of these processes vary from person to person, from age to age, and from one social context to another. Through an understanding of basic mental processes, a deeper understanding of people's problems and procedures for dealing with these problems can be gained.