Who does not want all kids to thrive? But what does that mean and how do you do it? Dr. Peter Samuelson deftly paves a path forward for practitioners and parents pointing to the essential elements of establishing a nurturing and transforming fit between youth and their surrounding communities. Drawing on cutting edge psychological theory, methodology, and practice, Dr. Samuelson emphasizes the often overlooked reality that thriving youth require thriving ecologies. His hopeful rendering of the topography of youth today conveys how to create a transformative fit between a young person and their environment allowing young people to grow into their strengths with and for and thrive. -- Pamela Ebstyne King, Ph.D. Peter Benson Professor Applied Developmental Science, Executive Director, Thrive Center, Fuller Theological Seminary, USA A synthesis of wisdom from youth, mentors, seasoned organizations, and scholars, Positive Youth Principles presents a critical analysis of what makes youth service organizations near perfect solutions for youth thriving. Samuelsons nine principles form a deeply insightful blueprint for why and how to make it all work. -- Andrea Hussong, Professor of Psychology and Neuroscience, University of South Carolina, USA This book offers a compelling look at how exemplary youth service organizations foster positive outcomes in marginalized youth. Through rich qualitative data and a principles-focused approach, Samuelson illuminates the crucial role of caring adult relationships, supportive communities, and opportunities for identity development. Essential reading for anyone working to create positive environments where all young people can flourish. -- Jean Rhodes, Frank L. Boyden Professor, University of Massachusetts, USA A fantastic book for those practitioners, institutional leaders and researchers who understand that Positive Youth Development is essential to face inequities and social fragilities in our contemporary societies. -- Ulisses Araújo, Full Professor at the School of Arts, Sciences and Humanities, University of Sao Paulo, Brazil