Today I Found Out's video: Spreading Disease the Friendly Way

The Friendship Paradox, first proposed by sociologist Scott L. Feld, demonstrates that your friends, on average, will not only have more friends than you, but, again on average, also be wealthier, more popular, and happier than you. This also has many other implications as well, and has also inspired research in other areas. For instance, Dr. Nicholas Christakis of Harvard and Dr. James Fowler of the University of California, San Diego, inspired by the Friendship Paradox, decided to do a study, where they contacted 319 random Harvard students and asked them to name some friends. This resulted in many friends listing the same friends and a very nice friendship tree at Harvard. They then found the more central nodes on that tree (the most popular students, that they named the "friends" group) tended to get sick from the Flu about 2 weeks before the average of the members of the other group that they called the "random student group." Further, this "friends group," also on average, got sick a full 46 days before the Flu epidemic peak. In both cases, monitoring individuals in this "friends" group provides an extremely early warning sign of some potential sickness making the rounds.