This volume consists of 15 chapters, each presenting a different segment of modern psychology. Topics range from biochemistry to the history of art, from epistemological arguments to the interplay of science and society; research methods include comparative, developmental, physiological, clinical, and statistical modeling. Each chapter also links current efforts to a shared history. Progress in these diverse activities is presented as the natural outgrowth of a common outlook on scientific psychology--a viewpoint known as Functionalism, first articulated around the turn of the century by William James, John Dewey, James Rowland Angell, Harvey Carr, and others. Part I takes a broad, historical perspective on the role of Functionalism in the development of scientific psychology. Essays here discuss the emergence of the Functionalist perspective; the importance of the Functionalists' appreciation of societal problems to the rapid progress and future contributions of psychology. Part II presents current research emphasizing biological aspects of psychological phenomena. It includes chapters on the evolutionary perspective that motivates comparative studies of behavior and cognition; clinical neuropsychology; how the coordinated development of psychophysiological and behavioral methods have provided insights in medicine and space travel; and research on the development of the nervous system. The next part focuses on phenomena of mental life by sampling current research on perception, cognition, and development: the Functionalist perspective in studies of cognitive development in children; changes in mental function that occur later in life and comprise a major challenge to research in cognitive gerontology; how one can best describe the structure of intelligence; and how the evolution of Western art reveals historic parallels between artistic expression and theories of perception. Part IV studies research on the interactions among people--the domain of social phenomena. Essays investigate the adaptive nature of social interactions; the social characteristics of giving and receiving; and how the behavioral effects of marijuana and patterns of usage vary by environment and social context.