Groups, and the ways in which they function, are of fundamental importance to human life. This engaging textbook offers a comprehensive introduction to group processes for students across the social sciences. Covering topics such as social influence, leadership, creativity, and intergroup relations, this book blends foundational work with up-to-date research to help students navigate the key theories and principles in a wide variety of contexts. Designed with teaching and learning in mind, each chapter features an outline, a chapter summary, review and discussion questions, and suggested multimedia and further reading resources. Recurring box features provide opportunities for deeper engagement with the issues raised. With an interdisciplinary focus throughout, this textbook is an ideal resource for upper-level undergraduate and graduate courses in psychology, as well as courses in business, communication, and related fields.