How do unconscious motivational needs (i.e., implicit motives) influence physiology, cognition, emotion, and behavior? What are the fundamental motives and how do they operate and interact with incentives? How can motives be measured and when is a motive measure valid? How are motives shaped by biology and culture, how do they influence political and societal processes? How can we use knowledge about implicit motives in clinical, business, and sport contexts to help people achieve their goals? These are some of the topics this comprehensive book presents in 27 clearly written chapters, contributed by leading authorities in the field. It represents a state-of-the-art reference for all researchers and practitioners interested in human motivation. The first section addresses fundamental questions about the nature of motivational incentives, the role of learning in motivation, and paradigms for the experimental study of motivation. It also portrays how motives, power, affiliation, achievement, sex, and autonomy shape experience and behavior. The second section presents classic and new approaches to motive assessment, including the use of computer-based content coding. In the third section, several chapters examine the cognitive, endocrine, neuroscientific, and cardiovascular correlates of motives. The last section explores how motives are involved in everyday experience and life-span-development, how they are shaped by culture and affect a host of real-life outcomes, ranging from sports, to management, politics, and to clinical implications. An appendix features a new coding system for the assessment of the need for sex. Bringing together exciting new research on a central topic in human motivation, this volume is an important addition to the libraries of scholars and practitioners.