Nicholas A. Christakis, MD, PhD, MPH, is a social scientist and physician at Yale University, specializing in network and biosocial science. He directs the Human Nature Lab and co-directs the Yale Institute for Network Science. As Sterling Professor of Social and Natural Science, he holds appointments in Sociology, Statistics, and Medicine. Dr. Christakis earned his BS from Yale in 1984, his MD and MPH from Harvard in 1989, and his PhD from the University of Pennsylvania in 1995. He was elected to the National Academy of Medicine in 2006 and the National Academy of Sciences in 2024. His research explores how health behaviors influence social networks through contagion. He has authored over 220 articles and acclaimed books, including Connected (2009) and Blueprint (2019).