This story by Clive Thompson from the NY Times Magazine examines networks and the signals that travel over them–only the network and the signals aren’t made of wires and electric impulses, the network is the social network of friends and relations and the signals are behaviors. A number of scientists have been using the mathematics of networks to analyze the impact that the behaviors of peoples’ friends and relations have on their own behaviors, and how certain behaviors sometimes get “transmited” through the network in ways startlingly like more physical networks. This article (free registration required) describes some of those scientists and their findings.