US: To scientists, laughter is no joke

So a scientist walks into a shopping mall to watch people laugh. There's no punch-line, writes Seth Borenstein for Associated Press. Laughter is a serious scientific subject, one that researchers are still trying to figure out.

Laughing is primal, our first way of communicating. Apes laugh. So do dogs and rats. Babies laugh long before they speak. No one teaches you how to laugh. You just do. And often you laugh involuntarily, in a specific rhythm and in certain spots in conversation.

You may laugh at a prank on April Fools' Day. But surprisingly, only 10% to 15% of laughter is the result of someone making a joke, said Baltimore neuroscientist Robert Provine, who has studied laughter for decades. Laughter is mostly about social responses rather than reaction to a joke.
Full report on the Associated Press site