Spiral Dynamics is a remarkably powerful model of human values-systems: What they are, how they are expressed, how they affect human interactions, how they emerge and change over time--and how they can shape the human future. Values-systems determine how a person chooses to spend time and resources, who that person agrees or disagrees with, what that person lives or dies for. In short, values-systems exert strong influence over almost every aspect of human thinking, decision-making and behavior.