"So many tangles in life are ultimately hopeless that we have no appropriate sword other than laughter," said Gordon Allport, an American psychologist and one of the founders of the study of personality. Scientists have studied the neurological effects of mirthful laughter since the 1970s. The founding father of gelotology, the scientific study of the psychological, physiological and neurological effects of laughter, was Norman Cousins, who used himself as a study participant. Since the publication of Cousins' ground-breaking results, numerous other studies have been conducted. The results indicate that mirthful laughter can stimulate the brain's regulation of hormones that control mood, stress, blood pressure and immune responses.
Norman Cousins, a layperson with no prior medical training, was the first to suggest that humor can improve physical health through its miraculous effects on the brain. When diagnosed with ankylosing spondylitis, a chronic inflammatory disease that can cause the joints in the spine to fuse, Cousins invented a healing system that combined massive amounts of vitamin C and humor. He recovered from near-paralysis and wrote the book "Anatomy of an Illness." He later used the same method to recover from a heart attack. Cousins' work has appeared in the prestigious New England Journal of Medicine.
Dr. Lee Berk, an immunologist at Loma Linda University's School of Allied Health and Medicine, has studied the effects of mirthful laughter on the regulation of hormones since the 1980s. Berk and his colleagues found that laughter helps the brain regulate the stress hormones cortisol and epinephrine. They also discovered a link between laughter and the production of anti-bodies and endorphins, the body's natural pain killers. Even the expectation that something funny is coming suffices to bring about positive effects, reports Dr. Berk.
The Brain's Reward System
Humor also helps the brain regulate the brain's dopamine levels, reports a Stanford research team in the December 4, 2003, issue of the journal Neuron. Dopamine, also known as "the reward hormone," is a neurotransmitter that regulates mood, motivation, attention and learning. Psychologically, dopamine triggers a feeling of pleasure. The Stanford team examined the brains of 16 study participants looking at cartoons that had been previously rated as funny or non-funny. They found that the funny cartoons activated a cluster of areas in the brain's limbic system that are crucially involved in the regulation of dopamine. The findings indicate that humor can have positive effects not only on mood, but also on motivation and learning.
Laughter and Serotonin
No hard data exist to confirm whether mirthful laughter has any direct effect on serotonin levels in the brain. Low levels of serotonin in the brain are linked to aggression, anxiety and depression. Both mirthful laughter and serotonin make you feel good. But the positive effects of mirthful laughter on your mood could be the result of increased dopamine and endorphin levels and decreased levels of the stress hormone cortisol.
Pathological laughter is laughter that is inappropriate, uncontrolled or dissociated from any stimulus. Numerous studies have shown that pathological laughter has no positive effects on mood or physical health. In fact, researchers believe pathological laughter results from a defect in the dopamine and serotonin systems. Serotonin re-uptake inhibitors, used to treat depression, have been effective in the treatment of pathological laughter, reports a research team led by Antonia Damasio, a leading expert in emotional regulation from University of Iowa. The research on pathological laughter shows that it is not laughter itself that has a positive effect on health but rather the underlying mirthfulness of non-pathological laughter.