Research Into Laughter Is Serious Business

Research Into Laughter Is Serious Business
By Will Dunham

WASHINGTON (Reuters) - Research into laughter -- how it sounds, what role it plays and how it originated -- is serious business, according to psychologists who think it's funny that so little is known about this quintessentially human expression.

Jo-Anne Bachorowski, a Vanderbilt University psychology professor, and Michael Owren, a Cornell University psychology professor, have set out to bring home the data about laughter.

``This is one of the most fundamental aspects of human behavior and we know so remarkably little about it,'' Bachorowski said in an interview.

``It can really tell us a lot about how humans interact with each other, how we manage to get along with each other, how we have different emotional stances with each other. I just think it's one of the most intriguing aspects of our daily interactions with other people,'' Bachorowski added.

In research appearing in Journal of the Acoustical Society of America, Bachorowski and Owren detail the acoustics of laughter. They found that the notion of laughter sounding like ''ha-ha-ha'' and ``tee-hee-hee'' is as wrong as it is hackneyed.

The researchers showed a series of 11 video clips to 97 young adult volunteers, including two funny ones. To provoke laughter, they showed the fake orgasm scene from the 1989 film ''When Harry Met Sally'' and a farcical corpse collection scene from the 1974 film ``Monty Python and the Holy Grail.'' The volunteers obliged by laughing a combined 1,024 times.

GRUNTS AND SNORTS

A detailed acoustical analysis found that the participants produced a variety of laughing sounds, including grunts and snorts. The researchers detected *** differences in the use of these sounds. Men used grunts and snorts more often than women. Women produced more song-like laughter using the tissues in the larynx involved in producing vowels and related sounds.

Laughs were surprisingly high-pitched. Women's laughter, on average, was two times as high-pitched as their normal speech, while men's laughter was 2.5 times as high-pitched as their normal voice. In fact, men's laughs sometimes were about the vocal pitch of a high ``C'' from a soprano singer.

``There was a tremendous amount of variety in the acoustics of the sounds that were produced,'' Owren said in an interview.

``There's a lot of noisy events or snorty events or grunty events going on in the laughter,'' Owren added.

The researchers sought to explain the *** differences.

``We found that listeners really don't like grunts and snorts. It doesn't do as much for them as the song-like laughter does. But they especially don't like those sounds when they're produced by females,'' Bachorowski said.

Earlier work by Bachorowski and Owren yielded interesting laughing facts. They found that people differ in the number and types of laughs depending upon the *** of their social partner and whether the other person was a friend or stranger.

Women's laughs had very high and variable vocal pitch when they were with male strangers. Women in the presence of a male friend laughed more often than women with a female friend or with a male stranger. But men laughed more freely with friends of either *** than with strangers of either ***.

LAUGHTER A WAY TO FORGE PARTNERSHIPS

Humans are alone in the animal kingdom in laughing (although some researchers suggest that chimpanzees produce sounds corresponding to laughter when tickled). Bachorowski and Owren are trying to figure out what first made people laugh.

The researchers hypothesize that laughter originated as a way for early humans to forge partnerships. It was preceded by the debut of the smile, which communicated a positive disposition to other individuals. But a more complex signal became necessary because smiles were easy to fake. Laughter -- much more easily detected when counterfeit -- was the answer.

``We think it really did play an important role in hominid evolution,'' Bachorowski said. ``Humans need other people. We rely on other people a great deal. And so we need to have behaviors and signals and expressions available to us that can facilitate the occurrence of cooperative behavior.''

``So with laughter, we think it's the sound that can make other people feel good. And if you make another person feel good, then they're going to be more likely to be predisposed to behave positively toward you,'' Bachorowski added.

Laughter is not simply a way to project happiness or friendliness, the researchers said. In fact, there are many types of laughter, including derisive and anxious laughter.

Owren said laughter might not be a method to express one's own emotions at all, but rather a way to influence the emotions of others. ``Perhaps the function of laughter is not for the laugher to be conveying information about one's emotional state to the listener, but rather the laughter is being used as a kind of a tool or a strategy by which a laugher can change the emotional state of the listener,'' Owren said.

To that end, the researchers are using advanced imaging techniques to observe what happens in people's brains when they hear laughter. They also want to determine whether derisive laughter differs acoustically from more positive laughter.

​