Tickling. The notion puts a gleam in the eye of older brothers everywhere. And for the very ticklish, those who dissolve into jelly at a mere touch, the very word can inspire panic.

A handful of psychologists, like Rodney Dangerfields of science, are struggling to gain respect from their chuckling colleagues and they say that understanding the mysteries of the tickle may improve treatment for depression and even schizophrenia.

"Anything one said about tickling tends to be taken frivolously," said Alan J. Fridlund, a psychologist at the University of California-Santa Barbara who studies humor, facial expressions like smiles, and tickling. "But it's deadly serious."

Tickling may offer insight into the most fundamental of human bonds - an idea put forward by no less venerable a scientific figure than Charles Darwin. And William Shakespeare, who mastered all of our emotions, asked in "The Merchant of Venice," "if you tickle us, do we not laugh?"

"The notion that tickling is a quirky little behavior someone does to annoy you is false, said Robert Provine, an expert on laughter and a professor of psychology at the University of marland. "Tickle is the development of communication between mothers and babies. And its an important part of the vocabulary of lovemaking."

And as these scientists study tickling en route to loftier scientific understanding of the human brain and its role in social behavior, they're answering many pressing questions along the way.

Continued