During a large disaster, like Hurricane Katrina, warnings get hopelessly jumbled. The truth is that, for warnings to work, it's not enough for them to be delivered. They must also overcome that human tendency to pause; they must trigger a series of effective actions, mobilizing the informal networks that we depend on in a crisis.
Millions of us track ourselves all the time. We step on a scale and record our weight. We balance a checkbook. We count calories. But when the familiar pen-and-paper methods of self-analysis are enhanced by sensors that monitor our behavior automatically, the process of self-tracking becomes both more alluring and more meaningful.
Though social eugenics was discredited long ago, we still often think of the genome in quasi-eugenic terms. When we read about the latest discovery of a link between a gene and a disease, we imagine that we've learned the cause of the disease, and we may even think we'll get a cure by fixing the gene.