Okay - I only know this and have time to say it because I told the instructor for the class I am helping with, epidemiology, that this article I read might lead to a good activity for the students. And guess what he said? Basically, "make it happen."
Researchers tracked flu cases last year. The study involved college students at Harvard. Students named their friends, and whoever they named were expected to have even more friends because they would be the popular people. Well, if the BMOC gets sick, a lot of people would be exposed to him. The researchers must have identified the popular folks and when they tested positive or went to the health clinic with flu symptoms, the scientists predicted that a little outbreak would occur a week later. They were right!