Gabriele Oettingen, PhD, is Professor of Psychology at New York University and the University of Hamburg, Germany. Dr. Oettingen's research differentiates among various types of thinking about the future and examines their developmental and situational origins, as well as their effects on the control of cognition, emotion, and behavior. She has pointed out the perils of positive thinking and discovered mental contrasting, an imagery-based self-regulation technique that, by drawing on nonconscious processes, is effective for mastering one's everyday life and long-term development. Dr. Oettingen has published in journals of social, personality, developmental, educational, health, clinical, organizational, and consumer psychology, as well as in neuropsychological and medical journals. Her work led to the creation of effective and easy-to-apply behavior change interventions, and she is the author or coauthor of several books in the area of behavior change. A. Timur Sevincer, PhD, is Assistant Professor in the Institute of Psychology at the University of Hamburg, Germany. Dr. Sevincer's primary research interest is motivation and self-regulation, including, for instance, the spontaneous use of self-regulation strategies, their effect on physiological energization, the effect of alcohol on motivation and self-regulation, and motivational underpinnings of migration toward cosmopolitan cities. Dr. Sevincer is the author or coauthor of more than 25 scholarly publications in such journals as Psychological Science, the Journal of Personality and Social Psychology, the Journal of Abnormal Psychology, Personality and Social Psychology Bulletin, and Motivation and Emotion. Peter M. Gollwitzer, PhD, is Professor of Psychology at New York University and the University of Konstanz, Germany. Dr. Gollwitzer's research examines how goals and plans affect people's cognition, affect, and behavior. He has developed various models of action control: the theory of symbolic self-completion (with Robert A. Wicklund), the Rubicon model of action phases (with Heinz Heckhausen), the auto-motive model of automatic goal striving (with John A. Bargh), the mindset model of action phases, and the theory of implementation intentions. In these theories, the underlying mechanisms of effective action control are delineated, and respective moderators are distilled. Dr. Gollwitzer's recent research focuses on developing easy-to-conduct but powerful behavior change interventions. He has published many influential journal articles, book chapters, and books.