How Laughter Works

"Bill Gates and the president of General Motors have met for lunch, and
Bill is going on and on about computer technology. 'If automotive
technology had kept pace with computer technology over the past few
decades, you would now be driving a V-32 instead of a V-8, and it would
have a top speed of 10,000 miles per hour,' says Gates. 'Or, you could have
an economy car that weighs 30 pounds and gets a thousand miles to a gallon
of gas. In either case, the sticker price of a new car would be less than
$50. Why haven't you guys kept up?' The president of GM smiles and says,
'Because the federal government won't let us build cars that crash four
times a day!'"

Why is that funny? Have you ever wondered about that? Human beings love to
laugh, and the average adult laughs 17 times a day. Humans love to laugh so
much that there are actually industries built around laughter. Jokes,
sitcoms and comedians are all designed to get us laughing, because laughing
feels good. For us it seems so natural, but the funny thing is that
laughter is a distinctly human response. As with language, human beings are
the only species capable of laughter. Laughter is actually a complex
response that involves many of the same skills used in solving problems.

Laughter is a great thing -- that's why we've all heard the saying,
"Laughter is the best medicine." There is strong evidence that laughter can
actually improve health and help fight disease. In this edition of How
Stuff Works, we'll look at laughter -- what it is, what happens in our
brains when we laugh, what makes us laugh and how it can make us healthier
and happier. You'll also learn that there's a tremendous amount that no one
understands yet!

What Is Laughter?

First of all, laughter is not the same as humor. Laughter is the
physiological response to humor. Laughter consists of two parts -- a set of
gestures and the production of a sound. When we laugh, the brain pressures
us to conduct both those activities simultaneously. When we laugh heartily,
changes occur in many parts of the body, even the arm, leg and trunk muscles.

If you want to get specific about it, it works like this: Under certain
conditions, our bodies perform what the Encyclopedia Britannica describes
as "rhythmic, vocalized, expiratory and involuntary actions" -- better
known as laughter. Fifteen facial muscles contract and stimulation of the
zygomatic major muscle (the main lifting mechanism of your upper lip)
occurs. Meanwhile, the respiratory system is upset by the epiglottis
half-closing the larynx, so that air intake occurs irregularly, making you
gasp. In extreme circumstances, the tear ducts are activated, so that while
the mouth is opening and closing and the struggle for oxygen intake
continues, the face becomes moist and often red (or purple). The noises
that usually accompany this bizarre behavior range from sedate giggles to
boisterous guffaws.

Behavioral neurobiologist and pioneering laughter researcher Robert Provine
jokes that he has encountered one major problem in his study of laughter.
The problem is that laughter disappears just when he is ready to observe it
-- especially in the laboratory. One of his studies looked at the sonic
structure of laughter. He discovered that all human laughter consists of
variations on a basic form that consists of short, vowel-like notes
repeated every 210 milliseconds. Laughter can be of the "ha-ha-ha" variety
or the "ho-ho-ho" type but not a mixture of both, he says. Provine also
suggests that humans have a "detector" that responds to laughter by
triggering other neural circuits in the brain, which, in turn, generates
more laughter. This explains why laughter is contagious.

Humor researcher Peter Derks describes laughter response as "a really
quick, automatic type of behavior." "In fact, how quickly our brain
recognizes the incongruity that lies at the heart of most humor and
attaches an abstract meaning to it determines whether we laugh," he says.

An interesting aside: One of the key features of natural laughter is its
placement in speech, linguists say. Laughter almost always occurs during
pauses at the end of phrases. Experts say this suggests that an orderly
process (probably neurologically based) governs the placement of laughter
in speech and gives speech priority access to the single vocalization
channel. This strong relationship between laughter and speech is much like
punctuation in written communication -- that's why it's called the
punctuation effect.

What Is the Purpose of Laughter?

Philosopher John Morreall believes that the first human laughter may have
begun as a gesture of shared relief at the passing of danger. And since the
relaxation that results from a bout of laughter inhibits the biological
fight-or-flight response, laughter may indicate trust in one's companions.

Many researchers believe that the purpose of laughter is related to making
and strengthening human connections. "Laughter occurs when people are
comfortable with one another, when they feel open and free. And the more
laughter [there is], the more bonding [occurs] within the group," says
cultural anthropologist Mahadev Apte. This feedback "loop" of
bonding-laughter-more bonding, combined with the common desire not to be
singled out from the group, may be another reason why laughter is often
contagious.

Studies have also found that dominant individuals -- the boss or the tribal
chief or the family patriarch -- use humor more than their subordinates. If
you've often thought that everyone in the office laughs when the boss
laughs, you're very perceptive. In such cases, Morreall says, controlling
the laughter of a group becomes a way of exercising power by controlling
the emotional climate of the group. So laughter, like much human behavior,
must have evolved to change the behavior of others, Provine says. For
example, in an embarrassing or threatening situation, laughter may serve as
a conciliatory gesture or as a way to deflect anger. If the threatening
person joins the laughter, the risk of confrontation may lessen.

Provine is among only a few people who are studying laughter much as an
animal behaviorist might study a dog's bark or a bird's song. He believes
that laughter, like the bird's song, functions as a kind of social signal.
Other studies have confirmed that theory by proving that people are 30
times more likely to laugh in social settings than when they are alone (and
without pseudo-social stimuli like television). Even nitrous oxide, or
laughing gas, loses much of its oomph when taken in solitude, according to
German psychologist Willibald Ruch.

Laughter on the Brain

The physiological study of laughter has its own name -- gelotology. And we
know that certain parts of the brain are responsible for certain human
functions. For example, emotional responses are the function of the brain's
largest region, the frontal lobe. But researchers have learned that the
production of laughter is involved with various regions of the brain. While
the relationship between laughter and the brain is not fully understood,
researchers are making some progress.

For example, Derks traced the pattern of brainwave activity in subjects
responding to humorous material. Subjects were hooked up to an
electroencephalograph (EEG) and their brain activity was measured when they
laughed. In each case, the brain produced a regular electrical pattern.
Within four-tenths of a second of exposure to something potentially funny,
an electrical wave moved through the cerebral cortex, the largest part of
the brain. If the wave took a negative charge, laughter resulted. If it
maintained a positive charge, no response was given, researchers said.

During the experiment, researchers observed the following specific activities:
 - The left side of the cortex (the layer of cells that covers the entire
surface of the forebrain) analyzed the words and structure of the joke.
 - The brain's large frontal lobe, which is involved in social emotional
responses, became very active.
 - The right hemisphere of the cortex carried out the intellectual analysis
required to "get" the joke.
 - Brainwave activity then spread to the sensory processing area of the
occipital lobe
(the area on the back of the head that contains the cells that process
visual signals).
 - Stimulation of the motor sections evoked physical responses to the joke.

This is different from what happens with emotional responses. Emotional
responses appear to be confined to specific areas of the brain, while
laughter seems to be produced via a circuit that runs through many regions
of the brain. (This means that damage to any of these regions can impair
one's sense of humor and response to humor, experts say.)

The Limbic System

When we look more closely at the areas of the brain involved with laughter,
the limbic system seems to be central. The limbic system is a network of
structures located beneath the cerebral cortex. This system is important
because it controls some behaviors that are essential to the life of all
mammals (finding food, self-preservation).

Interestingly, the same structures found in the human limbic system can
also be found in the brains of evolutionary ancient animals such as the
alligator. In the alligator, the limbic system is heavily involved in smell
and plays an important role in defending territory, hunting and eating
prey. In humans, the limbic system is more involved in motivation and
emotional behaviors.

Structures in the brain's limbic system, which controls many essential
human behaviors, also contribute to the production of laughter.

While the structures in this highly developed part of the brain
interconnect, research has shown that the amygdala, a small almond-shaped
structure deep inside the brain, and the hippocampus, a tiny,
seahorse-shaped structure, seem to be the main areas involved with
emotions. The amygdala connects with the hippocampus as well as the medial
dorsal nucleus of the thalamus.

These connections enable it to play an important role in the mediation and
control of major activities like friendship, love and affection and on the
expression of mood. The hypothalamus, particularly its median part, has
been identified as a major contributor to the production of loud,
uncontrollable laughter.

What Makes Us Laugh?

Laughter is triggered when we find something humorous. There are three
traditional theories about what we find
humorous:

The incongruity theory suggests that humor arises when logic and
familiarity are replaced by things that don't normally go together.
Researcher Thomas Veatch says a joke becomes funny when we expect one
outcome and
another happens. When a joke begins, our minds and bodies are already
anticipating what's going to happen and how it's going to end. That
anticipation takes the form of logical thought intertwined with emotion and
is influenced by our past experiences and our thought processes.

When the joke goes in an unexpected direction, our thoughts and emotions
suddenly have to switch gears. We now have new emotions, backing up a
different line of thought. In other words, we experience two sets of
incompatible thoughts and emotions simultaneously. We experience this
incongruity between the different parts of the joke as humorous.

The superiority theory comes into play when we laugh at jokes that focus on
someone else's mistakes, stupidity or misfortune. We feel superior to this
person, experience a certain detachment from the situation and so are able
to laugh at it.

The relief theory is the basis for a device movie-makers have used
effectively for a long time. In action films or thrillers where tension is
high, the director uses comic relief at just the right times. He builds up
the tension or suspense as much as possible and then breaks it down
slightly with a side comment, enabling the viewer to relieve himself of
pent-up emotion, just so the movie can build it up again! Similarly, an
actual story or situation creates tension within us.

As we try to cope with two sets of emotions and thoughts, we need a release
and laughter is the way of cleansing our system of the built-up tension and
incongruity. (According to Dr. Lisa Rosenberg, humor, especially dark
humor, can help workers cope with stressful situations. "The act of
producing humor, of making a joke, gives us a mental break and increases
our objectivity in the face of overwhelming stress," she said.)

Why Can't I Tickle Myself?

This is a little off the beaten laughter path, but believe it or not, some
research is being conducted in this area. In fact, researchers at the
University of California in San Diego have even constructed a "tickle
machine."

Some scientists believe that laughing caused by tickling is a built-in
reflex. If this is true, then, theoretically, you should be able to tickle
yourself. But you can't -- not even in the same area and the same way
someone else tickles you into hysteria! The information sent to your spinal
cord and brain should be
exactly the same.

But apparently, for tickling to work, the brain needs tension and surprise
-- something that's obviously missing when you tickle yourself. How the
brain uses this information about tension and surprise is still a mystery.

So What Does All This Mean to Our Health?

We've long known that the ability to laugh is helpful to those coping with
major illness and the stress of life's problems. But researchers are now
saying laughter can do a lot more -- it can basically bring balance to all
the components of the immune system, which helps us fight off diseases.

As we mentioned earlier, laughter reduces levels of certain stress
hormones. In doing this, laughter provides a safety valve that shuts off
the flow of stress hormones and the fight-or-flight compounds that swing
into action in our bodies when we experience stress, anger or hostility.
These stress hormones suppress the immune system, increase the number of
blood platelets (which can cause obstructions in arteries) and raise blood
pressure.

When we're laughing, natural killer cells that destroy tumors and viruses
increase, as do Gamma-interferon (a disease-fighting protein), T-cells,
which are a major part of the immune response, and B-cells, which make
disease-destroying antibodies.

Laughter may lead to hiccuping and coughing, which clears the respiratory
tract by dislodging mucous plugs. Laughter also increases the concentration
of salivary immunoglobulin A, which defends against infectious organisms
entering through the respiratory tract.

Laugh Your Way to Fitness

What may surprise you even more is the fact that researchers estimate that
laughing 100 times is equal to 10 minutes on the rowing machine or 15
minutes on an exercise bike. Laughing can be a total body workout! Blood
pressure is lowered, and there is an increase in vascular blood flow and in
oxygenation of the blood, which further assists healing. Laughter also
gives your diaphragm and abdominal, respiratory, facial, leg and back
muscles a workout. That's why you often feel exhausted after a long bout of
laughter -- you've just had an aerobic workout!

How Does Laughter Improve Our Mental Health?

The psychological benefits of humor are quite amazing, according to doctors
and nurses who are members of the American Association for Therapeutic
Humor. People often store negative emotions, such as anger, sadness and
fear, rather than expressing them.

Laughter provides a way for these emotions to be harmlessly released.
Laughter is cathartic. That's why some people who are upset or stressed out
go to a funny movie or a comedy club, so they can laugh the negative
emotions away (these negative emotions, when held inside, can cause
biochemical changes that can affect our bodies).

Increasingly, mental health professionals are suggesting "laughter
therapy," which teaches people how to laugh -- openly -- at things that
aren't usually funny and to cope in difficult situations by using humor.
Following the lead of real-life funny-doc Patch Adams (portrayed by Robin
Williams in a movie by the same name), doctors and psychiatrists are
becoming more aware of the therapeutic benefits of laughter and humor. This
is due, in part, to the growing body of humor and laughter scholarship (500
academicians from different disciplines belong to the International Society
for Humor Studies).

Why Don't We All Laugh at the Same Things?

Experts say that several obvious differences in people affect what they
find humorous. The most significant seems to be age.

Infants and children are constantly discovering the world around them. A
lot of what goes on seems ridiculous and surprising, which strikes them as
funny. What's funny to a toddler consists of short and simple concepts,
like an elephant joke.

Along with the ridiculous and the surprising, children -- much to their
parents' dismay -- also appreciate jokes where cruelty is present (it
boosts their self-assertiveness) and what we refer to as "toilet humor." To
children, a preoccupation with bodily functions is simply another way of
exploring their fascinating new environment.

The pre-teen and teenage years are, almost universally, awkward and tense.
Lots of adolescents and teens laugh at jokes that focus on sex, food,
authority figures and -- in typical rebellious style -- any subject that
adults consider off-limits. It is an insecure time of life and young people
often use humor as a tool to protect themselves or to feel superior.

As we mature, both our physical bodies and mental outlooks grow and change.
Since there is a certain amount of intelligence involved in "getting" a
joke, our senses of humor becomes more developed as we learn more. By the
time we're grown, we have experienced much of life, including tragedy and
success. In keeping with these experiences, our senses of humor are more
mature. We laugh at other people and ourselves in shared common
predicaments and embarrassments.

The adult sense of humor is usually characterized as more subtle, more
tolerant and less judgmental about the differences in people. The things we
find funny as a result of our age or developmental stage seem to be related
to the stressors we experience during this time. Basically, we laugh at the
issues that stress us out.

Another factor that affects what we find funny is the culture or community
from which we come. Have you ever laughed at a joke and realized that if
you were from anywhere else in the world, it just wouldn't be funny? It's a
fact of life that culture and community provide lots of fodder for jokes.
There are economic, political and social issues that are easy to laugh
about, but only the people living in that culture may understand it.
For example, a joke from a small country might not have universal appeal
because it would be so little understood. The big, influential,
much-observed United States might be the exception to this rule. Thanks to
media and movies, most people around the world know what is going on here.
So jokes about a situation in the United States can be enjoyed pretty much
across the globe.

When people say "that's not funny," theorist Veatch says they mean either
"It is offensive" or "So, what's the point?" For someone to find a joke or
situation offensive, he must be somewhat detached from the principle or
person being demeaned or put down in the joke. So racist and sexist jokes
are offensive to many people who feel strongly about fighting bigotry and
prejudice in the world. According to Veatch, when someone says, "So, what's
the point?" it indicates the absence of any moral or emotional attachment
or commitment to the joke's "victim."

Can Laughter Be Bad for Me?

Of course, if abdominal surgery has you in stitches (in stitches -- get
it?), you should not laugh too hard because you could accidentally damage
your sutures. If you've ever had cracked or broken ribs, you know that even
a weak giggle is agonizing!

So let's stick with the good laughter -- the kind that makes us happier and
healthier! Here are some tips to help you put more laughter in your life:

a. Figure out what makes you laugh and do it (or read it or watch it) more
often.

b. Surround yourself with funny people -- be with them every chance you get.

c. Develop your own sense of humor. Maybe even take a class to learn how to
be a better comic -- or at least a better joke-teller at that next party.
Be funny every chance you get -- as long as it's not at someone else's
expense!


by Debbie Selinsky
Copyright 1998-2000 Howstuffworks.com, Inc. All rights reserved.
http://www.howstuffworks.com/laughter.htm

janet paterson
53 now / 41 dx / 37 onset
a new voice: http://www.geocities.com/janet313/
613 256 8340 PO Box 171 Almonte Ontario Canada K0A 1A0