Douglas G. Mook is Professor Emeritus of Psychology at the University of Virginia. He has published widely in leading professional journals, including Psychological Research, American Psychologist, and the Journal of Comparative and Physiological Psychology, on such diverse topics as the nature of preferences, the problem of external validity in research, and the neuroendocrine control of ingestion in rats. Professor Mook is also the author of Motivation: The Organization of Action. He lives in New York City, where he teaches regularly at local colleges while cultivating his interest in operatic performance.