Ever wonder why teenagers are so quick to adopt Instagram, Snapchat, and other forms of social media? Or take up X Games sports such as skateboarding and snowboarding? This Alliance for Excellent Education report explains how changes in the brain make adolescents more likely to be influenced by their peers, take risks, and even become disengaged in school as their motivations change. The report also provides recommendations to help educators, parents, policymakers, and others navigate the changes students experience during adolescence and design learning environments that support adolescent learning and development.