Nicholas Christakis

Nicholas Christakis's picture
Sterling Professor of Social and Natural Science, Internal Medicine & Biomedical Engineering
Ph.D., Sociology, University of Pennsylvania, 1995
M.D., Harvard Medical School, 1989
M.P.H., Harvard School of Public Health, 1988
Areas of Interest: 
Network Science; Health, Medicine and Biosocial Science; Biodemography; Quantitative Methodology
17 Hillhouse Avenue, Room 303
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Nicholas A. Christakis, MD, PhD, MPH, is a sociologist and physician who conducts research in the areas of social networks and biosocial science. He directs the Human Nature Lab.  

His current research is mainly focused on two topics: (1) the social, mathematical, and biological rules governing how social networks form (“connection”), and (2) the social and biological implications of how they operate to influence thoughts, feelings, and behaviors (“contagion”).  His lab uses both observational and experimental methods to study these phenomena, exploiting techniques from sociology, computer science, biosocial science, demography, statistics, behavior genetics, evolutionary biology, epidemiology, and other fields.
To the extent that diverse phenomena can spread within networks in intelligible ways, there are important policy implications since such spread can be exploited to improve the health or other desirable properties of groups (such as cooperation or innovation).  Hence, current work in the lab involves conducting field experiments: some work involves the use of large-scale, online network experiments; other work involves large-scale randomized controlled trials in the developing world where networks are painstakingly mapped. Finally, some work in the lab examines the biological determinants and consequences of social interactions and related phenomena, with a particular emphasis on the genetic origins and evolutionary implications of social networks. 
The author of several books and over 150 articles, Christakis was elected to the Institute of Medicine of the National Academy of Sciences in 2006 and was made a Fellow of the American Association for the Advancement of Science in 2010.




  • N.A. Christakis and J.H. Fowler, “Social Contagion Theory: Examining Dynamic Social Networks and Human Behavior,” Statistics in Medicine, 32(4): 556-577 (February 2013); doi:10.1002/sim.5408
  • C.F. Chabris, B.M. Hebert, D.J. Benjamin, J. Beauchamp, D. Cesarini, M. van der Loos, M. Johannesson, P.K. E. Magnusson, P. Lichtenstein, C.S. Atwood, J. Freese, T.S. Hauser, R.M. Hauser, N.A. Christakis, D. Laibson, “Most Reported Genetic Associations with General Intelligence Are Probably False Positives,” Psychological Science, 23(11): 1314-1323 (November 2012); doi:10.1177/0956797611435528
  • B.E. Landon, N.L. Keating, M.L. Barnett, J.P. Onnela, S. Paul, A.J. O’Malley, T. Keegan, and N.A. Christakis, “Variation in Patient-Sharing Networks of Physicians Across the United States,” JAMA: Journal of the American Medical Association, 308(3): 265-273 (July 2012); doi:10.1001/jama.2012.7615
  • F. Fu, C.E. Tarnita, N.A. Christakis, L. Wang, D.G. Rand, and M.A. Nowak, “Evolution of In-Group Favoritism,” Nature Scientific Reports, 2: 460 (June 2012); doi:10.1038/srep00460
  • C.L. Apicella, F.W. Marlowe, J.H. Fowler, and N.A. Christakis, “Social Networks and Cooperation in Hunter-Gatherers,” Nature  481(7382): 497-501 (January 2012)
  • D. Rand, S. Arbesman, and N.A. Christakis, “Dynamic Social Networks Promote Cooperation in Experiments with Humans,” PNAS: Proceedings of the National Academy of Sciences  108 (48): 19193-19198 (November 2011); doi:10.1073/pnas.1108243108
  • J. Block, N.A. Christakis, A.J. O’Malley, and S. Subramanian, “Proximity to Food Establishments and Body Mass Index in the Framingham Heart Study Offspring Cohort over 30 Years,” American Journal of Epidemiology, 174(10): 1108-1114 (November 2011); doi:10.1093/aje/kwr244
  • M. Pachucki, P.F. Jacques, and N.A. Christakis, “Social Network Concordance in Food Choice Among Spouses, Friends, and Siblings,” American Journal of Public Health, 101(11): 2170-2177 (November 2011); doi:10.2105/AJPH.2011.300282
  • J.P. Beauchamp, D. Cesarini, M. Johannesson, M.J.H.M van der Loos, P.D. Koellinger, P.J.F. Broenen, J.H. Fowler, J.N. Rosenquist, A.R. Thurik, and N.A. Christakis, “Molecular Genetics and Economics,” Journal of Economic Perspectives, 25(4): 57-82 (Fall 2011)
  • N.A. Christakis and J.H. Fowler, “Social Network Sensors for Early Detection of Contagious Outbreaks,” PLoS One, 5(9): e12948. doi:10.1371/journal.pone.0012948 (September 2010)
  • L. Jin, F. Elwert, J. Freese, and N.A. Christakis, “Preliminary Evidence Regarding the Hypothesis that the Sex Ratio at Sexual Maturity May Affect Longevity in Men,” Demography 47(3): 579-586 (August 2010)
  • J.H. Fowler, and N.A. Christakis, “Cooperative Behavior Cascades in Human Social Networks,” PNAS: Proceedings of the National Academy of Sciences  107(12): 5334-5338 (March 2010)
  • L. Jin and N.A. Christakis, “Investigating the Mechanism of Marital Mortality Reduction: The Transition to Widowhood and Quality of Health Care,” Demography 46(3): 605-625 (August 2009)
  • J.H. Fowler, C.T. Dawes, and N.A. Christakis, “Model of Genetic Variation in Human Social Networks,” PNAS: Proceedings of the National Academy of Sciences  106(6): 1720-1724 (February 2009)
  • F. Elwert and N.A. Christakis, “Wives and Ex-Wives: A New Test for Homogamy Bias in the Widower Effect,” Demography  45(4): 851-873 (November 2008)
  • K.P. Smith and N.A. Christakis, “Social Networks and Health,” Annual Review of Sociology  34: 405-429 (August 2008)
  • M. Alexander and N.A. Christakis, “Bias and Asymmetric Loss in Expert Forecasts: A Study of Physician Prognostic Behavior with Respect to Patient Survival,” Journal of Health Economics  27(4): 1095-1108 (July 2008)
  • N.A. Christakis and J.H. Fowler, “The Spread of Obesity in a Large Social Network Over 32 Years,” New England Journal of Medicine  357(4): 370-379 (July 2007)
  • F. Elwert and N.A. Christakis, “Widowhood and Race,” ASR: American Sociological Review  71(1): 16-41 (February 2006)
  • N.A. Christakis and P.D. Allison, “Mortality After the Hospitalization of a Spouse,” New England Journal of Medicine  354(7): 719-730 (February 2006)

Courses and Seminars



  • SOCY 636, Biosocial Science


  • Yale Department of Medicine
  • Yale Institute for Network Science