What makes diversity unifying in some settings but divisive in others? We examine how the mixing of ethnic groups in German schools affects intergroup cooperation and trust. We leverage the quasi-random assignment of students to classrooms within schools to obtain variation in the type of...

Globally, 150 million adolescents report being victims of or engaging in peer-to-peer violence in and around school. One strategy to reduce this risk is to occupy youth in after-school programs (ASP). Yet, the question remains: how does peer group composition affect the effectiveness of an ASP?...

Frontmatter -- Contents -- Preface to the Paperback Edition. Prufrock Avoided -- Acknowledgments. The Continuous Life -- Prologue. How Diversity Trumps Ability: Fun at Caltech -- Introduction. Unpacking Our Differences -- PART ONE. UNPACKING THE TOOLBOX -- 1. Diverse Perspectives. How We See...