Leonard Sax, M.D., Ph.D., is a family physician, psychologist, and author of Girls on the Edge and Why Gender Matters. Also the founder and executive director of the National Association for Single Sex Public Education (NASSPE), Sax is an active lecturer and has appeared CNN, PBS, The Today Show, Fox News, NPR's Talk of the Nation, among many other high-profile media outlets. Sax lives in Exton, Pennsylvania.