Thematically, urban legends are all over the map, but several persistent elements do show up again and again. Typically, urban legends are characterized by some combination of humor, horror, warning, embarrassment, morality or appeal to empathy. They often have some unexpected twist that is outlandish but just plausible enough to be taken as truth.
In the story of the organ harvesters, you can see how some of these elements come together. The most outstanding feature of the story is its sense of horror: The image of a man waking up lying in a bathtub full of ice, with one less kidney, is a lurid one indeed. But the real hook is the cautionary element. Most people travel to unfamiliar cities from time to time, and Las Vegas is one of the most popular tourist spots in the world. The story also includes a moral lesson, in that the businessman ended up in the unpleasant predicament only after going to drink at a bar and then flirting with a mysterious woman.
This is what's called a cautionary tale. A variation of the cautionary tale is the contamination story, which has played out recently in the spate of reports about human body fluids being found in restaurant food. One of the most widespread contamination stories is the long-standing rumor of rats and mice showing up in soda bottles or other prepackaged food.
There are also a lot of contamination stories that have to do with the unintentional injection of drugs. One particularly pervasive legend reports that drug dealers have been coating temporary tattoos with LSD. The dealers give these tattoos to children, who put them on and absorb the LSD through their skin. Supposedly, this is a scheme to get the kids addicted to LSD so they become regular customers (a particularly doubtful notion, since LSD does not seem to be physically addictive). Despite repeated public announcements that this story is not true, concerned people continue to spread the word about these drug-laced tattoos, posting warnings in police stations, schools and other public places.
Not all urban legends deal with such morbid, weighty issues. Many of them have no cautionary or moral element at all: They are simply amusing stories or ordinary jokes told as if they really occurred. One common "news story" reports that a man took out an insurance policy on an expensive box of cigars, smoked them all and then tried to collect a claim, saying that they had been damaged in a fire. Another tale tells of a drunk driver who is pulled over by the police. The officer asks the man to step out of the car for a sobriety test, but just as the test is about to begin, a car veers into a ditch up the road. The officer runs to help the other driver, and the drunk man takes the opportunity to flee the scene. When he gets home, he falls fast asleep on the couch. In the morning, he hears a loud knocking on his door and opens it to find the police officer from the night before. The man swears up and down he was home all night, until the officer asks to have a look in his garage. When he opens the door, he's shocked to see the officer's police cruiser parked there instead of his own car.
This story about the police car, in various forms, has spread all over the world. It even made it into the movie "Good Will Hunting," relayed by one of the characters as if it had happened to one of his friends. In the next section, we'll look at how urban legends like this one spread, and explore why so many people believe them.