A few months ago, at my first introduction to performance art, I experienced about a half-hour of nearly-uncontrollable, entirely inappropriate laughter, featuring desperate attempts to chew through my lip or hold my breath to stem the tide, fake coughs in an attempt to disguise any escaping chortles, and just enough presence of mind for the little psychologist in my head to wonder Why is this happening?
When I recovered and turned to Google Scholar, I discovered that there is surprisingly little research on the physical manifestation of humor; the first page of results after querying “psychology laughter” returned only 2 items from this century – and only 3 that weren’t older than I was – and “psychology brain” fared little better. Psychology is apparently very serious work, and few scholars are willing to take on something as sporadic, difficult to elicit, and humorous as laughter.
I did, however, remember Robert Provine, the leading expert in the field who has literally written the book (and, more relevant for scientific credentials, a review article in Current Directions in Psychological Science) on the subject. I first encountered Provine’s work as a first-year graduate student in a methods class, dissected a 1992 article in which he investigated whether just the sound of laughter – without a person, without a stimulus, without any social context – will make people laugh.
The study appears to have its origin in a novelty item that a student provided – a “laugh box” that produced and 18-second recording of laughter. The box was brought to three of Provine’s classes (with 18, 49, and 61 students enrolled), and played 10 times in 10 minutes, with students noting whether they laughed or smiled after each playback. Between 80 and 100% of the students in each class reported smiling the first time they heard the laugh box, and 30 to 70% reported laughing. These numbers dropped very quickly, though – by the 5th trial, fewer than 1 in 10 were laughing, by the 7th trial only 1 in 10 were smiling, and but the 10th trial three-quarters of the students agreed that the sound was obnoxious.
Unfortunately, it’s not clear exactly what to conclude about this, besides that which any parent can tell you – the same sound played over and over gets very old very quickly, making what’s cute in a toy at the store an incitement to murder at home.
Many students laughed the first time the sound was played, yes, but does that mean that the sound of laughter triggers laughing the same way that seeing someone else yawn triggers more yawning? The students might have laughed more because of the absurdity and awkwardness of sitting in a psychology class listening to a laugh box. A contemplative education listserve I belong to was just a few months ago discussing solutions to the problems of students breaking out in giggles the first time that meditation is introduced in a course, with no laugh box around.
There is in fact a distinct problem for the contagious laughter hypothesis, which is that the 61-strong class laughed far less, even on the first trial: just over 30% in that largest class reported laughing, compared to 60-70% of the smaller classes. If the mere sound of laughter were contagious, then I would expect the large class to have the most laughter, because all it would take is one or two students laughing at the laugh box, and then other students might laugh in response to their laughter, with a snowball effect spreading throughout the classroom. It could be that this particular class was composed of more serious-minded students, or that word had gotten out and they knew the laugh box was coming, or that being in a very large group suppresses laughter. There just isn’t enough information in the study to know.
My search for more recent and more definitive answers to do with laughter took me to some interesting places. I expanded my vocabulary, now to include gelotophobes (people who fear being laughed at) and gelotophiles (on the other extreme, those who enjoy being laughed at, and presumably go on to careers in slapstick or stand-up comedy). It also led to the happy discovery that a favorite magazine, Mental Floss, has featured Robert Provine. While the scientist in me takes umbrage at the journalistic claim that Provine has “proved” anything, it also contained enticing hints of more recent research showing that the mere sound of laughter activates certain regions of the brain as if to prepare a laughing response.
Although the nature of magazine writing gave me little to go on, and I could not ultimately find any research by Provine involving the brain, I did find one study by European researchers that fits the bill. Twelve (right-handed) volunteers lay back in a brain scanner and listened to audio clips of speech, nonsense, laughter, and other sounds. Unlike language, laughter evoked activity mostly in the right brain, specifically regions known as the superior temporal gyrus, subcentral gyrus, and precentral gyrus. It’s the precentral gyrus that is particularly interesting, as it is thought to be part of the mirror neuron system that helps us understand and imitate what other people do. It’s not enough yet to say that hearing laughter may be as contagious as seeing a yawn, but it’s certainly provocative.
The most important thing that Mental Floss article provided me, though, was a sense of closure about the classic Provine study, specifically hat happened to the laugh box:
“He stashed the laugh box in his office, but had to remove it after a few coworkers began swinging by to push the button. The crazed laughter was driving him to the brink of violence.”
Perhaps I should consider that a very good excuse for why the study hasn’t been replicated. Not because the box has gone missing, but because attempts to replicate it might have led to murderous student riots.