What's so funny? Well, may be nothing

Under different circumstances, you would be chuckling softly, maybe giggling, possibly guffawing. I know that's hard to believe, but trust me. The results are just in on a laboratory test of the muffin joke.

Laughter, a topic that stymied philosophers for 2,000 years, is finally yielding to science. Researchers have scanned brains and tickled babies, chimpanzees and rats. They've traced the evolution of laughter back to what looks like the primal joke - or, to be precise, the first stand-up routine to kill with an audience of primates.

It wasn't any funnier than the muffin joke, but that's not surprising, at least not to the researchers. They've discovered something that eluded Plato, Aristotle, Hobbes, Kant, Schopenhauer, Freud and the many theorists who have tried to explain laughter based on the mistaken premise that they're explaining humor.

Occasionally we're surprised into laughing at something funny, but most laughter has little to do with humor. It's an instinctual survival tool for social animals, not an intellectual response to wit.

It's not about getting the joke. It's about getting along.

When Robert R. Provine tried applying his training in neuroscience to laughter 20 years ago, he naively began by dragging people into his laboratory at the University of Maryland, Baltimore County, to watch episodes of "Saturday Night Live" and a George Carlin routine. They didn't laugh much. It was what a stand-up comic would call a bad room.

So he went out into natural habitats - city sidewalks, suburban malls - and carefully observed thousands of "laugh episodes." He found that 80 percent to 90 percent of them came after straight lines like "I know" or "I'll see you guys later." The witticisms that induced laughter rarely rose above the level of "You smell like you had a good workout."

He found that most speakers, particularly women, did more laughing than their listeners, using the laughs as punctuation for their sentences. It's a largely involuntary process. People can consciously suppress laughs, but few can make themselves laugh convincingly.

"Laughter is an honest social signal because it's hard to fake," Professor Provine says. "We're dealing with something powerful, ancient and crude. It's a kind of behavioral fossil showing the roots that all human beings, maybe all mammals, have in common."

The human ha-ha evolved from the rhythmic sound - pant-pant - made by primates like chimpanzees when they tickle and chase one other while playing. Jaak Panksepp, a neuroscientist and psychologist at Washington State University, discovered that rats emit an ultrasonic chirp (inaudible to humans without special equipment) when they're tickled, and they like the sensation so much they keep coming back for more tickling.

He and Professor Provine figure that the first primate joke - that is, the first action to produce a laugh without physical contact - was the feigned tickle, the same kind of coo-chi-coo move parents make when they thrust their wiggling fingers at a baby. Professor Panksepp thinks the brain has ancient wiring to produce laughter so that young animals learn to play with one another.

The laughter stimulates euphoria circuits in the brain and also reassures the other animals that they're playing, not fighting.

NY Times