We all can appreciate “a good laugh”! It has been suggested that laughter occurs as a result of recognition of truth but is also triggered by exaggeration or ridiculousness.
Laughter can also be a response to anxiety — think of the “nervous laugh” — or a way of relieving it.1
Research has correlated types of laughter with social signals related to reward, affiliation, and dominance.2 By four months of age, infants laugh in response to social cues.3
Laughter and Psychological Disorders
Laughter has a significant social component and, like yawning, is notorious for being contagious. People laugh more often in the presence of others than when alone. A recent study revealed reduced laughter contagion among boys at risk for psychopathology. “Human laughter engages brain areas that facilitate social reciprocity and emotional resonance, consistent with its established role in promoting affiliation and social cohesion,” E. O’Nions and colleagues write. “We show that, compared with typically developing boys, those at risk for antisocial behavior in general (irrespective of their risk of psychopathy) display reduced neural response to laughter in the supplementary motor area, a premotor region thought to facilitate motor readiness to join in during social behavior. Those at highest risk for developing psychopathy additionally show reduced neural responses to laughter in the anterior insula. “These findings suggest that atypical processing of laughter could represent a novel mechanism that impoverishes social relationships and increases risk for psychopathy and antisocial behavior.”4
Pseudobulbar Affect (PBA) Could Help Scientists Understand Laughter
You may have seen television advertisements concerning drug treatment of pseudobulbar affect (PBA), a phenomenon that occurs in association with a number of neurologic disorders. The condition is characterized by sudden, frequent episodes of laughing and/or crying that can be socially disabling. Although it is estimated to affect up to two million people in the United States, it is currently under-recognized and undertreated.5
With PBA, laughter (and, more often, crying) is involuntary and doesn’t necessarily express how the person afflicted by the condition is feeling or thinking. It is believed to be caused by injury to the neurologic pathways that regulate the expression of emotion. Perhaps fittingly, while crying episodes have been associated with depression and poorer quality of life in PBA patients, laughter has not.6 Investigation into the causes of this pathologic laughter could shed some light on how and why people laugh.
Anecdotal Evidence for Laughter as a Treatment
In 1964, editor Norman Cousins was diagnosed with the degenerative disease ankylosing spondylitis, which was associated with constant pain and poor prognosis. Since Cousins believed that stress had contributed to his illness, he reasoned that positive emotions could improve it. He began watching funny television shows or movies, and asserted that 10 minutes of belly laughter resulted in 2 hours of pain free sleep that was not achievable with morphine. His subsequent recovery was chronicled in his popular book, Anatomy of an Illness as Perceived by the Patient, which became a made-for-TV movie in 1984 that starred Ed Asner.7
While it can’t be definitively concluded that laughter was the reason for Cousins’ turnaround, he survived 26 years after his ankylosing spondylitis diagnosis, and 36 years after being diagnosed with heart disease. His experience, and that of others have given rise to “laughter therapy” or so-called “laughter yoga” as an alternative therapy to manage pain and other conditions.
Is Laughter a Drug?
A recent European study found that social laughter increased pleasure and triggered endogenous opioid release in the brain’s thalamus, caudate nucleus, and anterior insula. Consequently, pain threshold was found to significantly increase in male and female volunteers after viewing laughter-inducing comedy in comparison with nonhumorous dramas. S. Manninen and colleagues reported, “Opioid receptor density in the frontal cortex predicted social laughter rates. Modulation of the opioidergic activity by social laughter may be an important neurochemical mechanism reinforcing and maintaining social bonds between humans.” 8
Therapeutic Effects of Laughing
Laughter also lowers cortisol levels, according to the results of a study of pediatric inpatients. Following a humor therapy program, salivary cortisol levels decreased and stress perception improved in comparison with children in a nonintervention group.9
A review titled “Therapeutic Benefits of Laughter in Mental Health,” noted that laughter decreases serum cortisol, epinephrine, and the dopamine catabolite 3,4-dihydrophenylacetic acid, which is associated with a reversal of the stress response.10 It also alters dopamine and serotonin activity, which are reduced in depression, and stimulates the secretion of pain-relieving endorphins. “Laughter therapy is effective and scientifically supported as a single or adjuvant therapy,” author J. Yim concludes.10
In a study involving hemodialysis patients, a month of hour-long weekly group sessions of simulated laughter, breathing, stretching exercises, and meditation combined with daily individual laughter sessions improved mood, symptoms, and other factors.11 Laughter yoga has also helped improve mood in adults with Parkinson’s disease.12
A study of 20,934 Japanese women and men aged 65 years and older found a 21% higher adjusted risk of cardiovascular disease and a 60% greater risk of stroke among those who reported never or almost never laughing in comparison with those who reported laughing on a daily basis.13 The authors of the report note that the association could not be explained by confounding factors such as depression.
In cancer patients being treated with radiation, three hour-long laughter therapy sessions were associated with a 14.12 point reduction in total mood disturbance compared to only a 1.21 point reduction in a control group that did not receive laughter therapy.14
In older diabetic and healthy adults, viewing humorous videos was associated with greater improvement in recall, learning, and visual recognition compared to a similar-aged control group who did not watch a video.15 In a group of people living in residential aged care homes, a six-week laughter yoga program was associated with a significant post-session increase in positive mood, happiness, and lower systolic blood pressure.16 And in depressed and lonely institutionalized individuals between the ages of 65 and 75 years, laughter therapy significantly reduced depression.17
These studies are just a few of the many investigations that have looked at the potential benefits of laughter.
The Bottom Line
For the most part, laughter benefits the young and the old, the sick and the healthy and, like smiling, transcends languages and cultures. Next time you find something amusing, try letting go with a big belly laugh. It’s more contagious than a virus and certainly more healthy to your mind, body, relationships, and outlook on life.
- Bown A. Am J Psychoanal. 2017 Jun;77(2):163-176.
- Wood A et al. PLoS One. 2017 Aug 29;12(8):e0183811.
- Mireault GC et al. Br J Dev Psychol. 2017 Sep 25.
- O’Nions E et al. Curr Biol. 2017 Oct 9;27(19):3049-3055.e4.
- Brooks BR et al. PLoS One. 2013 Aug 21;8(8):e72232.
- Thakore NJ et al. J Neurol Neurosurg Psychiatry. 2017 Oct;88(10):825-831.
- Cousins, Norman, Anatomy of an illness as perceived by the patient : reflections on healing and regeneration, introd. by René Dubos, New York : Norton, 1979.
- Manninen S et al. J Neurosci. 2017 Jun 21;37(25):6125-6131.
- Sánchez JC et al. Hosp Pediatr. 2017 Jan;7(1):46-53.
- Yim J. Tohoku J Exp Med. 2016 Jul;239(3):243-9.
- Heo EH et al. Complement Ther Clin Pract. 2016 Nov;25:1-7.
- DeCaro DS et al. Explore (NY). 2016 May-Jun;12(3):196-9
- Hayashi K et al. J Epidemiol. 2016 Oct 5;26(10):546-552.
- Kim SH et al. J Altern Complement Med. 2015 Apr;21(4):217-22.
- Bains GS et al. Altern Ther Health Med. 2015 May-Jun;21(3):16-25.
- Ellis JM et al. Australas J Ageing. 2017 Sep;36(3):E28-E31.
- Quintero A et al. Biomedica. 2015 Jan-Mar;35(1):90-100.