Why We Laugh
Do Animals Laugh?
While humans might fancy themselves as the only animal capable of laughter, evidence suggests otherwise. In fact, apes seem to laugh after a fashion. They make a distinctive open-mouthed 'play face' and pant rapidly.
"The 'ha, ha' noise of human laughter," Provine tells WebMD, "ultimately has its origins in the ritualized panting laughter of our primate ancestors." Some researchers have found laugh-like behavior in other animals, even in the rat.
But it's not just coincidence that all stand-up comics have been human. While they may laugh, animals -- with the possible exceptions of some primates -- don't seem to have a sense of humor.
So if not at jokes, what do animals -- and what did our ancestors -- laugh at? According to Provine, animal "laughter" follows tickling, rough and tumble play, or chasing games. Apes laugh at some of the same things that make infants laugh. While babies aren't known for subtle wit, they will squeal and laugh when you chase them or tickle them. In all likelihood, early adult humans -- before they started telling jokes -- laughed at the same sort of thing.
Which leads us to an interesting conclusion: Since laughter predates speech, the first human laugh predated the first joke by hundreds of thousands or years, if not millions. It's a long time to wait for a punch line.
Dying Laughing
Happily, laughing itself is seldom lethal. But in some people with underlying health conditions, occasionally, jokes can kill. For instance, some unlucky laughers have had heart attacks, strokes, and embolisms when cracking up.
According to Provine, there is some historical evidence that tickling was used as a method of torture and execution in centuries past. In one reported and exceedingly bizarre technique, a victim was tied up and the soles of his feet were covered with salt. A goat was then brought in to lick the salt, causing intense tickling. If kept up for long enough, the stress and exertion of laughing -- and squirming -- could have eventually brought on cardiac arrest or a brain hemorrhage.
Using 'Laugh Therapy'
We've all heard the claim that 'laughter is the best medicine.' And according to many media reports, laughter is a panacea that will heal your immune system, dull your pain, improve your memory, lower blood pressure, and perform other wondrous feats.
But does this mean that, soon, insurance companies will start covering your movie tickets to HMO-approved comedies? Is laughter really the best, or for that matter, any kind of medicine?
The research isn't clear. But nonetheless, the last few decades have witnessed the rise of "laugh therapy" and other approaches that are based on the notion that laughter is healing.
Wilson is a proponent. He calls himself a "joyologist" and teaches people, business groups, and aspiring laugh therapists how to laugh.

