Socrates. Galileo. Darwin. What did these geniuses have in common, besidesmangy beards? All three pondered one of the universe's profound mysteries: Why do we laugh when we're tickled?
While the answer still isn't clear, University of California psychologist Christine Harris, Ph.D., has solved a small piece of the puzzle. Ticklish laughter, she reports, doesn't require the presence of another person. That may not seem like a major revelation. But since people can't tickle themselves, many experts insisted that tickling required interpersonal contact.
Harris, instead, believed ticklish laughter is more like a reflex. But her theory seemed impossible to test--until she devised Mechanical Meg, a robotic arm designed to look like a tickling machine. Thus equipped, Harris blindfolded research subjects and left them alone with Meg. But while the participants thought they were being tickled by a machine, the culprit was actually an assistant hiding under a table. The subjects giggled and squirmed anyway, a finding that supports Harris's view that tickling doesn't depend on social contact. But did the subjects guffaw because they were being tickled, or because the idea of being tickled by a robot is funny?
