ABSTRACT
The introductory chapter serves to introduce two perspectives on adolescence: that adolescence is a period of turmoil, and that adolescence is the formative period in life. I open the chapter by showing that the emergence of a long adolescence is a relatively new historical phenomenon. The chapter provides a preliminary answer to the ‘turmoil or formative period’ question. A final answer is given in the last chapter of this book, after the presentation of systematic longitudinal research in the various domains of adolescent development.
