Researchers studying adolescent development have often identified that one size does not fit all. For a long time we have lacked the proper tools to explore these individual processes in adolescent development. Psychosocial Development in Adolescence: Insights from the Dynamic Systems Approach is a roadmap for encouraging wonder and discovery of these individual processes. Now it is time to make a difference and take seriously the individual processes when studying adolescent development. Dynamic Systems Approach (DSA) is the fundamental approach behind the roadmap. Like any forefront scientific investigation, DSA gives us new tools and methods to examine individual processes. It seems possible that widespread use of these techniques could spur a return to the kind of new approach that is now needed in adolescent research globally. Psychosocial Development in Adolescence: Insights from the Dynamic Systems Approach is a much needed call to join an important new approach. It encourages us all to ask new questions. It inspires us to share the questions we ask every day. It motivates us to keep asking until we find routes to the answers. In a world where understanding diverse and individual pathways is essential, the DSA approach offers a richer way to solve these problems as a worldwide community of curious people who wonder about the fundamental new insights of the adolescent development.Professor Katariina Salmela-Aro, Educational Sciences, University of Helsinki, Finland