The 8½ Laws of Rumor Spread Some rumors grind to a halt, while others circle the world. Why some ideas spread and others die. By: Taylor Clark

Skeptical or gullible, we all buy into rumors sometimes. Even Barbara Mikkelson, who runs the popular myth-debunking Web site Snopes.com with her husband David, admits she's swallowed some whoppers. "A friend told me that when his friend's daughter was off on vacation, she had a whirlwind romance with this charismatic guy," Mikkelson says. "When it was time for her to come home, he gave her a package. Inside was a ceramic coffin with a message on it: 'Welcome to the world of AIDS.' I believed that one hook, line, and sinker."

Rumors have a way of slipping under our mental defenses before we think to question them. The best ones sidestep common sense entirely. "Think of the lawsuits parents filed over subliminal messages in heavy metal songs," says Martin Bourgeois, a rumor researcher at Florida Gulf Coast University. "People believed Judas Priest was planting messages to make teenagers commit suicide; no one thought to ask, 'Why would a rock band want its audience dead?'"

Most of us don't like to think of ourselves as gullible. But we're especially likely to accept as true—and do our best to spread—tales that have several specific characteristics that take aim at our best defenses.