About the Authors Catherine A. Sanderson is the Manwell Family Professor of Life Sciences (Psychology) at Amherst College. She received a bachelor’s degree in psychology, with a specialization in Health and Development, from Stanford University, and received both master’s and doctoral degrees in psychology from Princeton University. Professor Sanderson’s research examines how personality and social variables influence health-related behaviors, such as safer sex and disordered eating. Her research also examines the development of persuasive messages and interventions to prevent unhealthy behavior and predictors of relationship satisfaction. This research has received grant funding from the National Science Foundation and the National Institutes of Health. Professor Sanderson has published more than 25 journal articles and book chapters four college textbooks high school and middle school health textbooks and a trade book, The Positive Shift, which examines how mind-set influences happiness, health, and even how long people live. Her latest book, Why We Act: Turning Bystanders into Moral Rebels, examines why good people often stay silent or do nothing in the face of wrongdoing. In 2012, she was named one of the country’s top 300 professors by the Princeton Review. Mark Zelman is a Professor of Biology at Aurora University, Aurora, Illinois. He received a bachelor’s degree in biology at Rockford College, with minors in chemistry and psychology. He received a PhD in microbiology and immunology at Loyola University of Chicago, where he studied the molecular and cellular mechanisms of autoimmune disease. During his postdoctoral research at the University of Chicago, he studied aspects of cell physiology pertaining to cell growth and cancer. Dr. Zelman supervises undergraduate research on streptococcal and staphylococcal infections, and mechanisms of antibiotic resistance. He teaches science education courses for high school teachers. He has published articles on microbiology, infectious disease, autoimmune disease, and biotechnology, and he has written two college texts on human diseases and infection control. Dr. Zelman works with the West Africa AIDS Foundation and other public health projects in the US and abroad. He is an officer of the Illinois State Academy of Sciences. iii