Most people modify their ways of speaking, writing, texting, and e-mailing, and so on, according to the people with whom they are communicating. This fascinating book asks why we 'accommodate' to others in this way, and explores the various social consequences arising from it. Communication Accommodation Theory (CAT), revised and elaborated over the past 40 years, has been applied to a wide range of situations, from families to courtrooms, and from media to hospitals, by means of diverse methodologies in many disciplines, and across numerous languages and cultures. Bringing together a team of experts, this book demonstrates how the theory can help us towards a greater understanding of interpersonal communication in a multitude of contexts. Finally, it examines the principles of the theory, identifying a range of avenues along which research can move forward in future.