Laughter in Brain, Body, and Community
Laughter is a funny thing. Consider: it is a reflex. Just as an eye’s iris will contract when exposed to a bright light or a baby’s face will turn towards a brush against its cheek, a person exposed to certain stimuli will find their facial muscles involuntarily contracting, their breathing becoming labored, their voice producing a series of noises, and their eyes watering. Stranger still, humans enjoy these odd little spasms: we punctuate our speech with them; we are attracted to mates who provoke them; we seek them out in our free time. But irises contract to protect their retinas; babies turn in order find their mother’s breast; what is laughter? Why does it exist? Laughter feels good, but is it always good? And how does humor – the art of fashioning entertainment from incongruities – relate to religion – the art of discovering truth from incongruities?
This is the first post in a series entitled “Seriously, Though” which examines the evolutionary and philosophical reasons for laughter and humor. However, before considering some possible whys, we need a foundation of whats.
Laughter is a behavior we share with other animals. Squirrels, dogs and rats emit repetitive noises when at play or during courtship – much like we do. (For some ridiculously adorable examples of research into rat tickling, check out this video.) Whereas the laughter of these more distant evolutionary relations isn’t immediately recognizable (much of rat laughter is at a register too high for us to hear unaided), the laughter of our closer cousins, monkeys and apes, is clearly recognizable to us. What’s more, gorillas that have been taught sign language laugh when being playful with words – perhaps the rudimentary beginnings of a joke. However, as far as we can tell, laughter reaches dimensions in humans not found elsewhere in the animal kingdom. In fact, even on a basic auditory level our laughs set us apart. Dogs and chimps produce an “ah-ah-ah” noise by breathing heavily. A human’s distinctive “ha” is shaped by our vocal cords. That’s a first hint of how heavily human laughter has been influenced by our ability to speak. More significantly, as a person grows, his sense of humor develops in-step with his body and mind. By one month of age, babies can smile. By four months, they laugh outright. Young children laugh mostly at things they see, but as their vocabulary grows they laugh at puns and word play. As they learn social rules and etiquette later in childhood, they laugh at relationship jokes. Each individual mirrors the development of our species as a whole: intelligence and language expands an auditory expression of play into a complex social and cultural phenomena. In other words, the laughter of rodents, dogs, and chimps becomes the humor of human society.
Laughter and humor occur in three overlapping domains: they are triggered in one’s mind, produce effects throughout one’s body, all within the context of one’s community. There is no “funny bone;” almost surprisingly, there is also no “laughter lobe” or “humorcampus” in the brain. Instead, the origin of a laugh depends on the subject of the humor. Jokes dependent on particular knowledge start in the brain’s memory and semantic areas; puns begin with phonological processing (even when the pun is read, not heard); jokes that violate social norms start with social reasoning. If the appropriate area finds a joke funny, it signals the ventromedial prefrontal cortex (which controls all reward processing). That then begins the full body laughter reaction. The funnier the joke, the stronger the signal to the ventromedial prefrontal cortex and the harder the laugh.
Besides the obvious actions – lips curling up, teeth bared, rapid breathing, vocalization, and eyes watering – the laughter reflex includes other, subtler changes to the body. Stress hormones in the blood drop; immunoglobulin levels in saliva increase. The rapid repeated muscle spasms reduce muscle tension. Heart rates decrease. And, of course, endorphins are dumped into the bloodstream to improve mood and thinking. In evidence of this last point, researchers have found that people with a keen sense of humor tend to be more optimistic, respond better to setbacks, and are better aware of options when making decisions.
Laughter is more than neurons and knee-slapping: it’s a social activity. Just like playing puppies, flirty squirrels, and tittering tickled rats, humans are 30 times more likely to laugh if there is another person present. And laughter is more than a personal pleasure – it is a bonding experience. Studies have shown that when perfect strangers laugh together they begin to like each other. In fact, as Arthur Koestler observed, humor is a unique mode of communication since it produces a common, predictable physiological response. Teachers have no sure way of knowing if their lessons impact their students; artists can’t tell if a painting or sculpture conveys their meaning to others; tragedians can only hope they provoke catharsis in their audience; but a comedian knows when she’s brought down the house. In other social interactions, people can be unreadable or even deceptive; but a laugh contains a spark of truth.
In fact, one could say laughter is always genuine. Once a laugh starts, the human body can’t tell the difference between real laughing and fake – it will produce the normal laugh response regardless. Try smiling, squinting, and boisterously bellowing “ha-ha-ha-ha” (no, really, please – try it right now!) and before too long you’ll probably find genuine chuckles mixed in with your contrived laughs. Do you feel ridiculous? More on that in a bit. But right now the point is: laughter is ridiculously contagious. Imagine a world where you could get a cold by tickling your own nose with a feather. Laughter does this due to an external and an internal feedback loop.
The external is obvious: one person’s laugh encourages another person’s laugh. This is why laugh tracks are added to sitcoms, and why stand-up comedians love a packed house. This is also why sometimes groups can laugh long and hard over small things – well beyond a joke’s normal laugh expectancy.
Dr. Itzhak Fried at UCLA made an interesting discovery. He was artificially stimulating portions of a patient’s brain (to control seizures) when he inadvertently stimulated laughter. When he asked his patient why she was laughing (knowing, of course, it was actually the switches he was flipping) she gave a long list of odd reasons: there was just something about the expression on his face, she explained, or his white lab coat, or the clock on the far wall… Everyone knows that funny things make people laugh. Dr. Itzhak demonstrated that the reverse can be true: a laugh can make things seem funny. It has been suggested that this comes from cross-talk between the nervous and endocrine systems. Although laughter typically begins as a neurological response – all those brain firings listed above – the endocrine system is responsible for many of the psychological and physiological effects. Neurons fire off signals nearly instantly, whereas hormones take their sweet biochemical time about things. Therefore, by the time your body settles into a good laugh, the brain says, “…Wait, what?” It then begins assigning explanations for the lingering emotions of the endocrine response. These explanations may be the same things that made it signal the ventromedial prefrontal cortex in the first place, or it might choose something else on hand – maybe even something not ordinarily funny at all. Of course this new reason to laugh prolongs the endocrine response… and forms the internal feedback loop. This is why even individuals can “get the giggles,” why sometimes hilarious moments are inexplicably not funny when relayed to someone else later, and why stand-up comedians prefer a warmed-up crowd. One laugh primes the pump for more to come. And remember, reader, when you fake laughed to provoke real laughter a moment ago? (If you didn’t, I declare you a stick in the mud!) Perhaps you thought, Well, yes I’m laughing a little now, but that’s because I feel silly doing this… That silly feeling was probably your brain attempting to explain what all that laughing was about.
Contagious laughter is a superb example of the full anatomy of laughter in synergistic motion: mind, body, and society influencing and feeding one another for a jolly good time. These elements can begin to explain why we laugh: laughter positively effects our perspective, improves our health, and helps connect us with others. But “why” answers are usually deep and stratified. Some people want more than this initial layer has to offer. Laughter pervades our lives. It is a complex and nuanced behavior that accesses the pleasure centers of our brain. Nothing like it could have evolved without significantly contributing to survival. Laughter’s health benefits are too minor and subtle to be a sole explanation. And besides, they explain nothing about how humor works. Why are jokes funny? These people who consider the evolutionary origins of laughter are called gelotologists. Their ideas will be the subject of the next three parts in this series about group harmony, relief after a crisis, and discovering incongruity.
I am not a gelotologist. Nor am I a neuroscientist, a primate trainer, an experienced rat-tickler, or even a great joke-teller. What I am is a reader. I am completely reliant on the following sources for all of the scientific content above. I didn’t want to fill my post with citations, but if you would like to know where I picked up any particular fact above, let me know. Thanks!
The Anatomy of Laughter. Classroom Video On Demand. Films Media Group, 2003. Web. 21 Oct. 2014.
Bellows, Alan. “Gelotology 101: Anatomy of the best medicine.” Alien Hand Syndrome and Other Too-Weird-Not-To-Be-True Stories. New York: Workman Publishing Company Inc, 2009. 95-99. Print.
Free Science Videos and Lectures Online. “Rats Laugh When You Tickle Them.” Online video clip. YouTube. YouTube, 11 July 2007. Web. 20 Oct. 2014
Koestler, Arthur. “Humor and Wit.” Encyclopedia Britannica. New York: Encyclopedia Britannica Inc, 2002.
Martin, Rod A. “Humor and Laughter.” Encyclopedia of Psychology. New York. 2000. Print.
Patterson, Francine and Gordon, Wendy. “The Case for the Personhood of Gorillas.” Animal-Rights-Library.com. n.p. n.d. Web. 10 Oct 2014 (Originally published: Cavalieri, Paola & Singer, Peter (eds.) The Great Ape Project. New York: St Martin’s Griffin, 1993. 58-77.)