**Lixing Sun *is Distinguished Research Professor in the Department of Biological Sciences at Central Washington University. He is the author of The Fairness Instinct: The Robin Hood Mentality and Our Biological Nature and the coauthor of The Beaver: Natural History of a Wetlands Engineer *.

**Lixing Sun *is Distinguished Research Professor in the Department of Biological Sciences at Central Washington University. He is the author of The Fairness Instinct: The Robin Hood Mentality and Our Biological Nature and the coauthor of The Beaver: Natural History of a Wetlands Engineer *.