Perhaps nowhere are we brought into more dramatic contact with the unsettling side of the principle of social proof than in the realm of copycat crime. Back in the 1970s, our attention was brought to the phenomenon in the form of airplane hijackings, which seemed to spread like airborne viruses. In the 1980s, our focus shifted to product tamperings, such as the famous cases of Tylenol capsules injected with cyanide and Gerber baby-food products laced with glass. According to FBI forensic experts, each nationally publicized incident of this sort spawned an average of thirty more incidents.
