Nicholas Christakis
Nicholas A. Christakis is a Greek-American sociologist and physician known for his research on social networks and on the socioeconomic, biosocial, and evolutionary determinants of behavior, health, and longevity. He is the Sterling Professor of Social and Natural Science at Yale University, where he directs the Human Nature Lab. He is also the Co-Director of the Yale Institute for Network Science.
Christakis was elected a Fellow of the Institute of Medicine of the National Academy of Sciences in 2006; of the American Association for the Advancement of Science in 2010; and of the American Academy of Arts and Sciences in 2017.
In 2009, Christakis was named to the Time 100, Time magazine's list of the 100 most influential people in the world. In 2009 and again in 2010, he was named by Foreign Policy magazine to its list of top global thinkers.As of 2020, he has published three books.
Early life
Christakis' parents are Greek. They had three biological children and then adopted two others, an African-American girl and a Chinese boy. His father was a nuclear physicist turned business consultant and his mother a physical chemist turned psychologist. He was born in New Haven, Connecticut in 1962 when both his parents were Yale University graduate students. His family returned to Greece when he was three, and Greek became his first language. He returned to the United States with his family at the age of six and grew up in Washington, D.C. He graduated from St. Albans School.Education
Christakis obtained a B.S. degree in biology from Yale University in 1984, where he won the Russell Henry Chittenden Prize. He received an M.D. degree from Harvard Medical School and an M.P.H. degree from the Harvard School of Public Health in 1989, winning the Bowdoin Prize on graduation.In 1991, Christakis completed a residency in Internal Medicine at the University of Pennsylvania Health System. He was certified by the American Board of Internal Medicine in 1993. He obtained a Ph.D. degree in sociology from the University of Pennsylvania in 1995. While at the University of Pennsylvania as a Robert Wood Johnson Clinical Scholar, he studied with Renee C. Fox, a distinguished American medical sociologist; other members of his dissertation committee were methodologist Paul Allison and physician Sankey Williams. In his dissertation, which was published as Death Foretold, Christakis studied the role of prognosis in medical thought and practice, documenting and explaining how physicians are socialized to avoid making prognoses. He argued that the prognoses patients receive, even from the best-trained American doctors, are driven not only by professional norms but also by religious, moral, and even quasi-magical beliefs.
Career
In 1995, Christakis started as an Assistant Professor with joint appointments in the Departments of Sociology and Medicine at the University of Chicago. In 2001, he was awarded tenure in both Sociology and Medicine. He left the University of Chicago to take up a position at Harvard in 2001. Until July 2013, he was a Professor of Medical Sociology in the Department of Health Care Policy and a Professor of Medicine in the Department of Medicine at Harvard Medical School; a Professor of Sociology in the Department of Sociology in the Harvard Faculty of Arts and Sciences; and an Attending Physician at the Harvard-affiliated Mt. Auburn Hospital.In 2013, Christakis moved to Yale University, where he is a Professor of Social and Natural Science in the Department of Sociology, with additional appointments in the Departments of Ecology and Evolutionary Biology; Statistics and Data Science; Biomedical Engineering; Medicine; and in the School of Management. He served as the Sol Goldman Family Professor of Social and Natural Science until 2018, when he was appointed as a Sterling Professor, the highest honor bestowed on Yale faculty.
From 2009 to 2013, Christakis and his wife, Erika Christakis, were Co-Masters of Pforzheimer House, one of Harvard's twelve residential houses. From 2015 to 2016, he served in a similar capacity at Silliman College at Yale University.
Research
Christakis uses quantitative methods. His work focuses on network science and biosocial science, and it has also involved evolutionary biology, evolutionary psychology, behavior genetics, epidemiology, demography, and sociology. He is an author or editor of five books, more than 180 peer-reviewed academic articles, numerous editorials in national and international publications, and at least three patents. His laboratory is also active in the development and release of software to conduct experiments and other studies.Studies by Christakis and James H. Fowler, beginning in 2007, suggested that a variety of attributes like obesity, smoking, and happiness, rather than being solely individualistic, also arise via social contagion mechanisms over some distance within social networks. Other work in the Christakis and Fowler labs has used experimental methods to study social networks, and has broadened to use many data sets and approaches. In 2010, they demonstrated, using an experiment, that cooperative behavior could spread to three degrees of separation. In a TED talk, Christakis summarizes the broader implications of the role of networks in human activity.
In 2009, his group extended the study of social networks to genetics, publishing in PNAS: Proceedings of National Academy of Sciences a finding that social network position may be partially heritable, and specifically that an increase in twins' shared genetic material corresponds to differences in their social networks. In 2011, Fowler and Christakis published a follow-up paper on "Correlated Genotypes in Friendship Networks" in PNAS, advancing the argument that humans may be "metagenomic" with respect to the people around them. Further work on this topic included "Friendship and Natural Selection" in PNAS in 2014. In 2012, in a paper in Nature, the group analyzed the social networks of the Hadza hunter gatherers, showing that human social network structure appears to have ancient origins. Christakis and his colleagues did similar work mapping the networks of the Nyangatom people in 2016. His group has also demonstrated that social networks are deeply related to human cooperation. These ideas are explored in his 2019 book, Blueprint: The Evolutionary Origins of a Good Society.
In 2010, Christakis and Fowler published a paper regarding the use of social networks as 'sensors' for forecasting epidemics. In another TED talk, Christakis describes this effort. A follow-up paper in 2014 documented the utility of this approach to forecast trends, again based on the "friendship paradox," using Twitter data.
Beginning in 2010, Christakis and his colleagues initiated a program of research to deploy social networks to improve health and other social phenomena—for example, facilitating the adoption of public health innovations in the developing world, or demonstrating the utility of autonomous agents in optimizing coordination in groups online.
The 2017 Nature paper on bots initiated a program of work on "hybrid systems" composed of humans and machines that reshape how humans interact not with the machines, but with each other. A paper published in 2020 in PNAS extended this idea by showing that physical robots could modify conversations among people interacting in groups. Christakis has argued that "the effects of AI on human-to-human interaction stand to be intense and far-reaching, and the advances rapid and broad, we must investigate systematically what second-order effects might emerge, and discuss how to regulate them on behalf of the common good."
Christakis' lab has been supported by grants from the National Institutes of Health, by the Pioneer Program of the Robert Wood Johnson Foundation, by the Bill & Melinda Gates Foundation, and by other funders. In 2019, his lab received support to extend their work to studies of the human microbiota from the Nomis Foundation.
Physician
Christakis has practiced as a home hospice physician and in consultative palliative medicine. He took care of indigent, home-bound, dying patients in the South Side of Chicago while at the University of Chicago, in the period from 1995-2001. During this time, he was also active in translating research results into national policy changes with respect to end-of-life care in the USA; for instance, he testified before the US Senate Special Committee on Aging in 2000.In Boston, from 2002 to 2006, Christakis worked as an attending physician on the Palliative Medicine Consult Service at Massachusetts General Hospital. In 2006, he moved to Mount Auburn Hospital. In 2013, he moved to the Department of Medicine at Yale University.
Works
Books
- Death Foretold: Prophecy and Prognosis in Medical Care
- Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives - with James Fowler
- Blueprint: The Evolutionary Origins of a Good Society
His second book, Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives, was co-authored with James Fowler and appeared in September 2009. It was awarded the "Books for a Better Life" Award in 2009 and has been translated into 20 languages. Connected draws on previously published and unpublished studies and makes several new conclusions about the influence of social networks on human health and behavior. In Connected, Christakis and Fowler put forward their "three degrees of influence" rule, which theorizes that each person's social influence can stretch to roughly three degrees of separation before it fades out.
Christakis' third book, Blueprint: The Evolutionary Origins of a Good Society, was published by Little, Brown Spark in March 2019. It made the New York Times Best Seller list in its debut week. It was widely and favorably reviewed. For instance, Bill Gates described the book as "optimistic and terrific." Blueprint explores the idea that evolution has given humans a suite of beneficial capacities, including love, friendship, cooperation, and learning; humans have innate proclivities to make a good society, one that is similar worldwide. “For too long,” Christakis writes, “the scientific community has been overly focused on the dark side of our biological heritage: our capacity for tribalism, violence, selfishness, and cruelty. The bright side has been denied the attention it deserves.”
Christakis has also co-edited two clinical textbooks on end-of-life care, published by Oxford University Press.
Scientific papers
Free speech advocacy
At Harvard, in 2012, he and his wife, Erika Christakis, came to the defense of minority students who were using satire to criticize the elite final clubs at that institution. They suggested that the critics might be "more concerned with ugly words than the underlying problems" and that policing free expression on campus "denies students the opportunity to learn to think for themselves." Their argument expressed confidence in the capacity and maturity of Harvard students to discuss contentious issues.
At Yale, in 2015, they were involved in a controversy related to the regulation of Halloween costumes. On October 29, 2015, Christakis' wife Erika Christakis, a Lecturer on Early Childhood Education at the Yale Child Study Center, wrote an e-mail to Yale undergraduates on the role of free expression in universities; she argued, from a developmental perspective, that students might wish to consider whether administrators should provide guidance on Halloween attire or whether students might wish to be allowed to "dress themselves." This e-mail was in response to a long earlier e-mail sent to undergraduates by a group of 14 administrators at Yale which suggested students be careful when choosing Halloween costumes, and which provided links to recommended and non-recommended costumes. The e-mail played a role in protests on campus that received national attention in the United States. Christakis and his wife were criticized by some students for placing "the burden of confrontation, education, and maturity on the offended." But other students pointed out that Erika Christakis was defending the rights to free expression of all Yale students and expressing confidence in them and in their capacity to discuss and confront such issues among themselves. Ninety-one Yale faculty members signed a letter supporting the Christakises, and this letter noted that the Christakises themselves distinguished support for freedom of expression from supporting the content of such expression. Despite Christakis' belief that Yale students could discuss controversial issues among themselves, and his confidence in their ability to do so, he stepped down from his role at Silliman College eight months later, at the end of the academic year, a step The Atlantic later decried.
In a subsequent Op-Ed in The New York Times, Christakis argued: "Open, extended conversations among students themselves are essential not only to the pursuit of truth but also to deep moral learning and to righteous social progress." A year later, commentators condemned how students, administrators, and faculty had behaved at Yale. In her only published remarks regarding what happened, a year later in October 2016, Erika Christakis described the circumstances that she had faced in an Op-Ed published in The Washington Post.
The incident led to some students being called members of "Generation Snowflake". In January 2016, Bill Maher expressed consternation at how the Yale students had behaved. In April 2017, an episode of The Simpsons titled "Caper Chase" satirized the events, with one character saying: "We also need to hire more deans to decide which Halloween costumes are appropriate." Also in 2017, a short documentary was released about the episode, arguing that they reflected a collision between "old values" centered on reason and debate, on the one hand, and "administrative bloat" and a shift to a "consumer mentality" on the other. The New York Times published a coda regarding the episode in August 2018, upon Christakis' appointment as a Sterling Professor, Yale's highest faculty rank, in which Christakis noted that he "was eager to make himself useful to Yale's mission."
The 2015 occurrences at Yale have been discussed in at least 20 non-fiction books. Blackford provides a very precise and comprehensive timeline. Some of these books noted the "sexism" and "irony" that, in a key episode that was part of the events, the students wished to hold Christakis responsible for his wife's email. Murray summarizes statements by students based on his review of extensive video footage released by the students themselves of the events in the quad, and he notes Christakis' emphasis on "our common humanity." Many of the books have expressed concern at the "illiberal" actions of the students at Yale. The behavior of the students also sparked a minor controversy at Harvard Law School when a student there wrote a piece decrying the Christakis' treatment as "fascism" in the Harvard Law Record; criticized for publishing the piece, the Record's liberal editor-in-chief wrote that his role was "editor-in-chief, not thought-policeman-in-chief."
Christakis has spoken publicly about the events only rarely. In an October 2017 interview with Sam Harris, he discussed parts of the situation he faced, framing the events at Yale in the broader context of what was happening on many campuses during that time period; Harris noted that Christakis had "the imperturbability of a saint." In March 2019, Christakis told Frank Bruni that, partly in response to the events, he worked to complete a long-standing book project on the origins of goodness in society.
In April of 2020, Christakis expressed concern that, in the setting of the COVID-19 pandemic, hospitals and medical schools were seeking to silence faculty and staff who were highlighting problems with the response; he stated that “clamping down on people who are speaking is a kind of idiocy of the highest order."