"Sports hysteria" is a type of emotional contagion, where fans of the same team are all carried away by the same emotion. Dr. Stephanie Preston is a researcher of emotions and decision making, and she talks about how not displaying emotion is also a type of emotional contagion and is likely a consequence of the fact that we don't want to transmit out-of-control or negative emotions in a professional setting. It's a fascinating peek into altruism, empathy, and feelings. Dr. Stephanie D. Preston, PhD is Professor of Psychology and University of Michigan Faculty Ombuds. She received her PhD from the University of California, Berkeley. Her research is on the interface between emotion and decision making, focusing on how people process others’ emotions and how this affects offerings of help and on how people allocate resources. She has written a book titled, The Altruistic Urge: Why We’re Driven to Help Others.