Sex? Social standing? Social justice? With this breakthrough study of the motivational forces behind human behavior, and grounded in the most up-to-date psychological research available, Dr. Steven Reiss explains the 16 desires and values that shape our behavior-and shows how the ways we prioritize them determines our personality. "Well-explained in lay readers' terms." (Library Journal ) "An exciting new way to think about ourselves, an authoritative, research-based understanding of why we do the things we do." (Ellen Langer, Ph.D., author of Mindfulness) "Offers valuable insight into such matters as why some interpersonal relationships are enduringly satisfying and others are not." (Professor Richard J. McNally, Harvard University) "Reiss' system can improve our working relationships and enhance our professional lives." (Ruth Luckasson, J.D., Regents' Professor and Professor of Special Education, University of New Mexico)