Since college days, I’ve tackled big problems using the smallest practical tools that can be spread easily throughout society. My earliest project involved Sesame Street and others for a behavioral intervention to prevent a leading cause of death of young children—being struck by a car. In national trials in New Zealand, more than 50% of families used these simple tools. I applied this same thinking to help thousands of military families during the Gulf War. In the 1990s, I launched the largest youth violence prevention study in the US (PeaceBuilders), getting noticed in People Magazine. Today, I work on spreading evidence-based kernels and behavioral vaccines like the PAX Good Behavio