Companies have never invested more in transformation—or wasted more on failed attempts. Finally, a science-based, practical guide to making change stick. Market volatility. AI. Regulatory uncertainty. Geopolitical risk. Leaders know they must adapt faster than ever—yet most transformation programs still fail to deliver their expected outcomes, with enormous costs to companies, shareholders, and the broader economy. But some companies do succeed. In How Change Really Works, Boston Consulting Group experts Julia Dhar, Kristy R. Ellmer, and Philip Jameson show that these successes aren't random—they're connected by a common set of principles and practices. Interweaving rich examples, decades of research in behavioral science, interviews with executives and employees, and their own experience leading change, Dhar, Ellmer, and Jameson offer seven principles that form the core of a truly human-centered approach to successful organizational change. Admonitions such as "Get true agreement, not false alignment"; "Give people agency, not just involvement"; and "Expect take up to be earned, not automatic" are some of the principles that offer a fresh look at what it takes to really change an organization. The second part of the book moves into execution mode, providing a five-phase guide—informed by science and packed with tips, checklists, and hacks—that will help your transformation beat the odds and succeed. Change doesn't fail because people resist; it fails because leaders misunderstand how people really change. Whether you're launching a new change program or stuck in a stalled one, How Change Really Works is your essential guide.