Nicholas Christakis M.D., Ph.D.,

Nicholas A. Christakis, M.D., Ph.D., M.P.H., is an internist and social scientist who conducts research on social factors that affect health, health care, and longevity. He is Professor of Medical Sociology in the Department of Health Care Policy at Harvard Medical School; Professor of Medicine in the Department of Medicine at Harvard Medical School; and Professor of Sociology in the Department of Sociology in the Harvard Faculty of Arts and Sciences.

Christakis received his B.S. from Yale University in 1984, his M.D. from Harvard Medical School and his MPH from the Harvard School of Public Health in 1989, and his Ph.D. from the University of Pennsylvania in 1995. He was elected to the Institute of Medicine of the National Academy of Sciences in 2006.

His current research focuses on health and social networks, and specifically with how ill health, disability, health behavior, health care, and death in one person can influence the same phenomena in others in a person's social network. This work involves the application of network science and mathematical models to understand the dynamics of health in longitudinally evolving networks. To the extent that health behaviors such as smoking, drinking, or unhealthy eating spread within networks in intelligible ways, there are substantial implications for public health and health policy. This body of work has also engaged the spread of emotional states such as happiness, depression, and loneliness within social networks. Other very recent work has examined the spread of altruism and the genetic determinants of social network structure. Along with his long-time collaborator, James H. Fowler, Christakis had authored a book on social networks, published in 2009, Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives. This book has been translated into over a dozen foreign languages. He was named by Time magazine to their annual list of the 100 most influential people in the world in 2009.

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 two books).