NICHOLAS A. CHRISTAKIS

Nicholas A. Christakis, MD, PhD, MPH, is a social scientist and physician at Yale University who conducts research in the fields of network science, biosocial science, computational social science, and various other fields. His current work focuses on how human biology and health affect, and are affected by, social interactions and social networks. Dr. Christakis directs the Human Nature Lab and is the Director of the Yale Institute for Network Science. He is the Sterling Professor of Social and Natural Science at Yale University, appointed in the Departments of Sociology; Statistics and Data Science; Ecology and Evolutionary Biology; Biomedical Engineering; Medicine; and the School of Management.

Dr. Christakis received his BS from Yale in 1984, his MD from Harvard Medical School and his MPH from the Harvard School of Public Health in 1989, and his PhD from the University of Pennsylvania in 1995. He was elected to the National Academy of Medicine in 2006; the American Association for the Advancement of Science in 2010; the American Academy of Arts and Sciences in 2017; and the National Academy of Sciences in 2024.

In 2009, Christakis was named by Time magazine to their annual list of the 100 most influential people in the world. In 2009 and in 2010, he was listed by Foreign Policy magazine in their annual list of Top 100 Global Thinkers.

Dr. Christakis began his career at the University of Chicago in 1995, where he was appointed as a Professor in the Departments of Sociology and Medicine. He moved his lab to Harvard University in 2001, where he was again appointed as a Professor in the Departments of Sociology and Medicine. While at Harvard, he also served as the Master of Pforzheimer House in Harvard College. In 2013, he moved his lab to Yale University.

One line of work in his lab focuses on how health and health behavior in one person can influence analogous outcomes in a person’s social network, via social contagion. This work involves the application of statistical and mathematical models to understand the dynamics of diverse phenomena in longitudinally evolving networks. This work also uses large-scale experiments to examine the spread of ideas, altruism, emotions, and health behaviors along network connections online and offline. It has involved large-scale randomized controlled field trials in the developing world directed at improving public health (e.g., in Honduras, Uganda, and India). And it has also involved online experiments that manipulate human social interactions in large groups of people so as to understand the origins and implications of collective action.

A second line of work has examined the genetic and evolutionary determinants of social network structure, showing that social interactions have been shaped by our genome, and also shape it, with related projects that have mapped networks of populations in Tanzania and Sudan who live as all humans did 10,000 years ago. This line of work also explores the physiology of human social interactions, including the role of the microbiome and chemosignaling.

A third line of work has used artificial intelligence (AI) agents (“bots") to affect social processes online in “hybrid systems” of humans and machines.

His laboratory actively develops software and date tools to study social phenomena, and releases these resources publicly. Breadboard allows scientists to conduct online experiments accurately and efficiently. Trellis allows scientists to map social networks in diverse, demanding settings around the world.

Christakis is active in teaching, both in the classroom and in the lab. He has mentored students and postdocs from diverse fields, ranging across sociology, economics, anthropology, political science, statistics, applied math, physics, computational biology, medicine, public health, and other fields.

Dr. Christakis is the author of over 220 articles and several books. His influential book, Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives (2009), documented how social networks affect our lives and was translated into twenty foreign languages. His book, Blueprint: The Evolutionary Origins of a Good Society (2019) was a New York Times bestseller and was translated into over ten languages. His book Apollo’s Arrow: The Profound and Enduring Impact of Coronavirus on the Way We Live (2020) was also translated into over ten languages.

Dr. Christakis’ past work was focused on topics related to end-of-life care, such as hospice care, widowhood and caregiver burden, ICU decision-making, and the role of prognostication in medicine (about which he has written three books, including clinical textbooks).

Dr. Christakis has advised startups and established corporations, such as Whoop, Apple, Gallup, Virgin, MasterCard, Consensus AI, and others. A company called Activate Networks was spun out from his lab in 2010.