Chapter 2, ‘Adolescence’ sets the scene for the book by beginning with an understanding of the developmental process. Changes occurring during adolescence in a variety of areas are explored, including: physical, brain, cognitive, and social cognitive developments. These changes at an individual level are associated with changing interactions with others, and so there are sections on identity development and on family and peer relationships. There is a particular focus on emotion and emotion regulation development, as this is of particular importance for the fresh approach outlined in this book. The chapter concludes by challenging the notion that adolescence is inevitably a time of strife, difficulty, and conflict and it highlights theories of adolescence that can help understand why some adolescents and young adults have more difficulties during this time of life than do others.