Have you heard of the disease called ‘cachinnation’? It’s a doozy. Here are the symptoms: involuntary contraction of abdominal and facial muscles; rapid, rhythmic spasms of the diaphragm and intercostal muscles of the ribcage, accompanied by exhalations that are usually audible as a noise similar to a cough, wheeze, or yelp. The spams come in bouts lasting anywhere from half a second to half a minute or more; they often occur successively and can leave the victim gasping for air or in extreme (albeit very rare) cases cause death by asphyxiation. Prolonged cases usually result in activation of the tear ducts, causing redness of the eyes and face. Some victims experience urinary incontinence, weakness in the legs, or involuntary flailing of limbs.
In persons afflicted by cachinnation the symptoms may be caused by a touch in particular locations on the body, often the abdomen, armpits, or feet. There is also a psychological element to cachinnation: the symptoms can be triggered by seeing or hearing certain events or phrases, including, most alarmingly, simply witnessing the symptoms of cachinnation in another person. It is extremely contagious.
The bad news is that despite years of dedicated research, scientists and doctors have been unable to determine why exactly cachinnation occurs, nor why it manifests in the way it does. The really bad news is that cachinnation has been found in 100% of people tested for it.
The good news is that it’s just laughter—and I’m hoping that when you realize the ridiculous truth of what I’ve just written you will be afflicted by a small bout of it yourself. Is laughter not the strangest thing?
Scientists do know some things about laughter, the main thing being that it has much more to do with making social connections in general than it does with responding to humour in particular. You are 30 times more likely to laugh when you are with someone else than when you are by yourself. There is a strong correlation between the amount of laughter in a marriage and its longevity. Laughter is used in very nuanced ways to convey attitudes of acceptance, agreement, interest, and engagement with other people, and to alleviate stressful situations, pain, and embarrassment, among other things.
We are very attuned to laughter and its meanings, and while laughter is one of the earliest social expressions learned as an infant, studies have shown that it is not until their 30s and 40s that most people have fully developed their ability to decipher and understand all its subtleties.
There are two categories of laughter with very different social and physiological attributes: there is the more forced, polite laughter that is used in unfamiliar or stressful social settings. This is the laughter of nuance and layers of meaning that you are not able to fully understand until well into adulthood. It registers in the regions of the brain associated with thinking about how someone else is feeling. Then there is the uncontrollable, spontaneous belly laugh that occurs most often among close friends (and in children). It is picked up more prominently by the auditory pathways of the brain, and it is the kind of laughter that is most contagious.
It is also the kind of laughter that makes laughter so bizarre. When else do people feel comfortable making such primal hoots and squawks in front of others? There are the timeless, non-embarrassing hahas and heehees, but there is an endless variety of laughs beyond. There are the snorters and the howlers, the wheezers, the sniggerers. There is the “engine failing to start on a cold winter morning” laugh. There is the “excited chimpanzee”, the “maniacal chipmunk”, the “giant guinea pig”, the “suffocating donkey”, and of course the “hyena at play”. I myself fall under the “hoot owl doing a victory dance” category at times. What’s your laugh like?