WHAT'S SO FUNNY?(psychologist Richard Wiseman researches humor)

One Saturday evening in late June, the master of ceremonies at the Ice House, a comedy club in Pasadena, California, told the audience that they were in for a special treat: Dr. Richard Wiseman, a British scientist who was on a quest to determine the world's funniest joke, was going to come out and enlist the audience's help. The m.c., Debi Gutierrez, would tell jokes that particularly appealed to Americans who had visited Wiseman's humor Web site, and he would tell jokes favored by the British.

Wiseman bounded up and perched on a stool facing Gutierrez, a brassy woman in her early forties. "May I call you Richard?" she asked.

"You can call me what you want," Wiseman said.

"Dr. Dick!" she said. The audience whooped, and Wiseman offered a game smile. In a navy-blue T-shirt, khakis, and tortoise-rimmed glasses, with a Vandyke beard balancing his baldness, he looked like a particularly helpful store manager at the Gap. In fact, at the age of thirty-five, Wiseman--a professor at the University of Hertfordshire and the director of its Perrott-Warrick Research Unit--is Britain's most recognizable psychologist, famous for such mass-participation experiments as determining whether people can most easily detect lies told on television, on the radio, or in print. (It's on the radio.) Since last fall, he has been conducting a global humor study at LaughLab.co.uk, a Web site where visitors submit jokes and rate other people's jokes on a five-point scale called, somewhat unrigorously, the Giggleometer. When the experiment began, Wiseman posed for publicity photographs wearing a lab coat and holding a clipboard as he scrutinized a student wearing a chicken suit who was crossing a road. One photographer shouted, "Could the guy playing the scientist move to the left?," and Wiseman cried, "I am a scientist."

The experiment was so popular--the LaughLab site got three million hits in the first five days--that Wiseman's server blew out. He now has a repository of forty thousand jokes, some two-thirds of which are so racist, violent, or dirty that he can't post them for the site's visitors, a good number of whom, judging by their submissions ("What's brown and sticky? A stick!" cropped up three hundred and fifty-three times), won't be eligible for membership in the Friars Club for some years to come.

At the Ice House, Gutierrez read a Viagra joke and botched the punch line. Then it was Wiseman's turn. He is not a joke-teller by nature, and his recital was almost apologetic: "Guy goes to the doctor, who gives him a checkup. 'How long have I got to live, doc?' 'Ten.' 'Ten what? Weeks? Months?' 'Ten, nine, eight . . .' "

There are many ways that people laugh in a comedy club. There's what you might call the Anticipator ("He just mentioned Monica Lewinsky! This'll be great!"), the Clapper ("It's about time someone called bin Laden a terrorist!"), the Aficionados' Simper, the Coerced Snicker, the You-Crossed-the-Line "Ooh" (reserved for a Kennedy joke), the Gut Buster, and so forth. But there's only one kind of silence.