15 April

Nicholas Christakis is a professor of medicine and sociology, and studies social networks. What's he's found is amazing, and gives us new ways to understand how our everyday social life interacts with our online social life, and how our health and happiness are profoundly linked to our social networks. Even more interestingly, he shows how the social network is itself a living thing, semi-independent of the individuals in it. Some of the findings - obesity is contagious. We can become fat if our friends are fat. Broadway musicals succeed or not depending on the social network of the people who put them together.