Professor of Psychology, College of Science, San Diego State University; Researcher on teens and Generation Z; Author, Generations: The Real Differences Between Gen Z, Millennials, Gen X, Boomers, and Silents - and What They Mean for America's Future ( 2023), iGen: Why Today's Super-Connected Kids Are Growing Up Less Rebellious, More Tolerant, Less Happy -- and Completely Unprepared for Adulthood (2017), The Narcissism Epidemic (2009), and Generation Me (2006); Co-Author, “Associations Between Adolescent Depression and Self-harm Behaviors and Screen Media Use in a Nationally Representative Time-diary Study” (2021, Research on Child and Adolescent Psychopathology)