Laughter: It Does a Body Good

Navajos have a tradition called the Laughing Party, honoring a newborn’s first laugh, usually at around six weeks old. The person who makes the baby laugh first plays an important role in the child’s life.

Laughter relates to making and strengthening human connections. People laugh when they’re comfortable with one another, laughing creates a bond, and bonding promotes further comfort, and trust. Laughter facilitates social cooperation, as smiling and laughing show that we feel good and also influences the behavior of others towards us. The sounds of laughter communicate playfulness, not hostility.

Studies have shown that people are 30 times more likely to laugh in social settings than when they are alone (and without pseudo-social stimuli like television). The reason laughter can be contagious has roots in the neurological mechanism of laugh detection. Dr. Robert Provine, a leading researcher on the science of laughter, theorizes that humans have an auditory laugh detector, a neural circuit in the brain that responds exclusively to laughter. Once triggered, the laugh detector activates a laugh generator, a neural circuit that causes us to produce laughter.

Researchers posit that the first human laughter may have begun as a gesture of shared relief at the passing of danger. The relaxation that results from a bout of laughter inhibits the biological fight-or-flight response. Laughter may have then 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, and if the threatening person joins in, the risk of confrontation may lessen.

Humor is one specialized way to evoke laughter, but most laughter doesn't follow jokes. Provine’s research has involved eavesdropping on people in public places, where he found that maybe one of ten laughter episodes followed anything resembling a joke. Instead, laughter typically followed utterances like "Well, gotta go," or "Where'd you get that shirt?" Laughter can be generated simply by delight, and enjoyment of the company of others.

Although humans are not the only species that laughs, we are the only one to laugh in our particular way, with all the gestures and sounds. The Encyclopedia Britannica describes human laughter as our bodies performing "rhythmic, vocalized, expiratory and involuntary actions.” From sedate giggles to boisterous guffaws, laughter engages muscles of the diaphragm, abdomen, lungs, face, legs and back.

The ability to laugh helps those coping with illness and life stresses. Research suggests that laughter can bring balance to the immune system, which helps us fight off disease.

By reducing levels of certain stress hormones, 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.

Laughing lowers blood pressure, and increases blood flow and oxygenation of the blood, which assists healing. It increases natural killer cells which destroy tumors and viruses; 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 that leads to hiccupping and coughing clears the respiratory tract by dislodging mucous plugs. Laughter increases the concentration of salivary immunoglobulin A, which defends against infectious organisms entering through the respiratory tract.

People often store negative emotions, such as anger, sadness and fear, rather than expressing them. When negative emotions are held inside, they can cause biochemical changes that can affect our bodies negatively. Laughter provides a way for these emotions to be harmlessly released.

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© 2008 Jenny Chapin
Valley Acupuncture & Healing Arts - Greenfield, MA - 413-522-3816