The largest component, 714 people, of the social network studied
by Fowler and Christakis, on Dec. 8, 2009. Infected individuals
are colored red, friends of infected individuals are colored
yellow, and circle size is proportional to the number of friends
infected. A movie tracks the spread of the flu from Sept. 1
through Dec. 31, 2009. Credit: Nicholas Christakis Your friends
are probably more popular than you are. And this “friendship
paradox” may help predict the spread of infectious disease.
Nicholas Christakis, professor of medicine, medical sociology
and sociology at Harvard University, and James Fowler, professor
of medical genetics and political science at the University of
California, San Diego, used the paradox to study the 2009 flu
epidemic among 744 students. The findings, the researchers say,
point to a novel method for early detection of contagious
outbreaks. Analyzing a social network and monitoring the health
of its central members is an ideal way to predict an outbreak.
But such detailed infor