Laughter is part of the universal human vocabulary. All members of the human species understand it. We’re born with the capacity to laugh.
Laughter is social and contagious. We laugh at the sound of laughter itself.
One of the remarkable things about laughter is that it occurs unconsciously. You don’t decide to do it. While we can consciously inhibit it, we don’t consciously produce laughter. That’s why it’s very hard to laugh on command or to fake laughter. (Don’t take my word for it: Ask a friend to laugh on the spot.)
Laughter provides powerful, uncensored insights into our unconscious. It simply bubbles up from within us in certain situations.
But we do know that laughter is triggered by many sensations and thoughts, and that it activates many parts of the body.
When we laugh, we alter our facial expressions and make sounds. During exuberant laughter, the muscles of the arms, legs and trunk are involved.
We also know that laughter is a message that we send to other people. We know this because we rarely laugh when we are alone (we laugh to ourselves even less than we talk to ourselves).Laughter is social and contagious. We laugh at the sound of laughter itself.
The first laughter appears at about 3.5 to 4 months of age, long before we’re able to speak. Laughter, like crying, is a way for a preverbal infant to interact with the mother and other caregivers.
Contrary to folk wisdom, most laughter is not about humor; it is about relationships between people.
We don’t decide to laugh at these moments. Our brain makes the decision for us. These curious “ha ha ha’s” are bits of social glue that bond relationships.

AN EVOLUTIONARY PERSPECTIVE. We believe laughter evolved from the panting behavior of our ancient primate ancestors. Today, if we tickle chimps or gorillas, they don’t laugh “ha ha ha” but exhibit a panting sound. That’s the sound of ape laughter. And it’s the root of human laughter.
When we laugh, we’re often communicating playful intent. So laughter has a bonding function within individuals in a group. It’s often positive, but it can be negative too. There’s a difference between “laughing with” and “laughing at.” People who laugh at others may be trying to force them to conform or casting them out of the group.
No one has actually counted how much people of different ages laugh, but young children probably laugh the most. At ages 5 and 6, we tend to see the most exuberant laughs. Adults laugh less than children, probably because they play less. And laughter is associated with play.

How Laughter Works

Why is something 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 humans are one of the only species that laughs. 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.

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.

What is the purpose of laughter?

One philosopher believes that the first human laughter may have begun as a gesture of shared relief at the passing of danger. 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”. 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, 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. 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.

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. 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. 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 device moviemakers 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. Actually, 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.

Why can’t I tickle myself?

Some scientists believe that laughing caused by tickling is a built-in reflex because even babies do it. If this is true, then you should be able to tickle yourself…but you can’t, can you? Even if you try to tickle yourself in exactly the same way that another person tickles you, you don’t laugh. Why is this? The information sent to your spinal cord and brain should be exactly the same. Apparently for tickling to work, the brain needs tension and surprise. When you tickle yourself, you know exactly what will happen…there is no tension or surprise. How the brain uses this information about tension and surprise is still a mystery, but there is some evidence that the cerebellum may be involved.

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. 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? 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?” 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.”

Laughter and 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.
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!
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, doctors and psychiatrists are becoming more aware of the therapeutic benefits of laughter and humor. Here are some tips to help you put more laughter in your life:
 Figure out what makes you laugh and do it (or read it or watch it) more often.
 Surround yourself with funny people — be with them every chance you get.
 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!
The average adult laughs 17 times a day.
That different people find different jokes funny can owe to any of a number of factors, including differences in personality, intelligence, mental state and probably mood. But, the majority of people recognize when a situation is meant to be humorous.
Those who don’t get it may be depressed or have something else happening in their life.
One humor researcher has been trying to identify the connection between mood and responsiveness to humor. He had originally thought that mood played a vital role in whether a person responded to humor. Someone feeling happy, for instance, would be much more inclined to laugh at a joke than someone feeling sad. Individuals seem to respond to humor in different ways that can’t be predicted from their mood.
Humor is a very central element in human activity. Researchers like to think of it as the distorted mirror of the mind. It’s creative, perceptual, analytical and lingual. If we can figure out how the mind processes humor, then we’ll have a pretty good handle on how it works in general.
More people are getting into this research as they realize how little has been done on it. There’s also a greater recognition that humor plays an intrinsic role in our lives and that we can learn a great deal about the human mind if we better understand it.

What’s So Funny and Why:
Laughter and the Brain

Laughter…it’s fun…it’s funny…but why do we do it? Why can’t you tickle yourself? What part of the brain is responsible for laughter and humor? There are not many answers to these questions because there have not been very many experiments on the topic of laughter. Part of the reason for this is that laughter is not a big clinical problem. People do not go to the doctor because they are laughing and feel good. On the other hand, there are a some people with brain damage that MAY cause uncontrollable, abnormal laughter. Also, there is a type of epilepsy with gelastic seizures…these seizures cause people to laugh.
Everyone smiles and laughs. Even monkeys and apes have some facial expressions that are similar to human smiles. It is possible that smiling, laughing and tickling are used to create bonds between babies and parents. When a parent tickles a baby and the baby responds with a smile or laugh, the parent laughs and smiles too. In this way, the baby and parent get to know one another and the baby learns all about laughter by watching and responding to a parent.

Is Laughter the Best Medicine?

The physiological study of laughter has its own name…”gelotology”.
Research has shown that laughing is more than just a person’s voice and movement. Laughter requires the coordination of many muscles throughout the body. Laughter also:
1. increases blood pressure
2. increases heart rate
3. changes breathing
4. Reduces levels of certain neurochemicals (catecholamines, hormones).
5. Provides a boost to the immune system.
Can laughter improve health? It may be a good way for people to relax because muscle tension is reduced after laughing. There are some cases when a good deep laugh may help people with respiratory problems by clearing mucus and aiding ventilation. Perhaps laughing can also help cardiac patients by giving the heart a bit of a workout. Some hospitals even have their own “Humor Rooms,” “Comedy Carts,” and clown kids in attempts to speed a patient’s recovery and boost morale.
However, laughter is NOT ALWAYS good medicine. There are a few cases when laughing actually CAUSED a heart attack or a stroke. Also, immediately after abdominal surgery, people should not laugh too hard because they could tear out their stitches accidentally. Care should also be used in patients with broken ribs. So, try not to be too funny around these people.