Urban legends are stories with plots that are repeated and are told to be believed. In short, this is the definition of what folklorists labeled as Testimonial or Migratory Legends in pre-industrial Europe. In Northern Europe, there is a good catalogue of types by the Norwegian folklorist Reidar Th. Christiansen. Because there were no debunkers in the pre-industrial world, these legends were told for centuries and diffused over national and ethnic boundaries.

Our modern urban legends tend to have shorter life spans because they are easily debunked and modern consumers of folklore have a built in cynicism, but they stories perform much like their pre-industrial counterparts. At least one of them - the Vanishing Hitchhiker - has pre-industrial roots, so at least in this one case, the old tradition survives.

The field of urban legends is enormous and volumes can (and have been) written on the subject. The late Alan Dundes wrote some early things on the subject, but the leading authority and author on the subject is Utah folklorist Jan Harold Brunvand (1933- ).