A detailed exploration and integration of behavior change research into a unifying multi-level fractal theory, Intentional Change Theory (ICT), showing the science behind sustained, desired change at the individual, dyadic, team, organizational, community, and country levels.Change is constant and ever-present in everyday life. Yet sustained, desired change is much harder to grasp. Bringing together 50 years of research into behavior change, The Science of Change explores Intentional Change Theory (ICT) and highlights how the model can be used to understand and support lasting change. In this book, Richard E. Boyatzis presents a unifying theory for lasting change with an examination of each phase and principle in this multi-level, fractal theory and provides examples of sustained, desired change at the individual, dyadic, team, organization, community, and country levels. The five phases of ICT describe a cycle of change. It starts with a vision of an ideal self, examines the real self, and then creates a learning agenda for getting closer to the vision before applying it through experimentation and practice and building resonant relationships to enable the entire process. It highlights how the ideal self and a shared vision are the drivers of change, that goal setting and problem solving suppress openness to new ideas and people, and that resonant relationships are characterized by shared vision, shared compassion, and shared energy. The framework described in this book is equally applicable to getting better at playing the guitar, achieving a department sales target, rallying a community to action over a toxic spill, or mobilizing a country to fight a pandemic.