Jasmine Aguayo
- Nov 20, 2019
- 4 min read

The Power of Laughter

When Psychology Changes Your Physiology

By Jasmine Aguayo

Whether you giggle, chuckle, or guffaw, laughter feels good. Yet, its effect on the body is more significant than the euphoria we experience. Adding extra laughter to your days leads to a healthier heart and a longer life. It can reduce stress, strengthen your immune system, and prevent cardiovascular disease. Even though there are psychological benefits to faking it, not all laughter is powerful on a physiological level.

Types of Laughter

According to the Society of Neurosciences, laughter can be analyzed through its three distinct parts: emotional, motor, and cognitive. Not every laugh contains each one. The reason we laugh will influence which ones are triggered. [Kirsch. pg 563]

There are two main types of laughter based on brain activity and facial expression. The Duchenne laugh is characterized by identifying the presence of the Duchenne smile.

The Duchenne Smile

The main factor distinguishing a laugh is the Duchenne smile, characterized by the crinkle and glimmer in the eyes.

This smile is a part of genuine laughter. It involves the merriment we associate with a good rib tickler.

Spontaneous and involuntary
Authentic, strong, positive emotional response
Change in eye physiology (pupil dilation)
Examples:
Response to humor/comedy
Playful behavior
Moments of happiness

Non Duchenne Smile

In some circumstances, our emotions are far from joyous, yet we laugh. The sides of the mouth will still turn up, but the eyes muscles lack movement. There is an absence of “crows feet” at the corners, a sign of happiness. We do not need to be educated to recognize this false expression. Even a child has the capability of identifying it.

When we witness someone producing this laugh, it is not contagious. We do not feel happy looking at their face like we do when their eyes are smiling.

Often voluntary
Cognitive and motor response
Lacks genuine positive emotion
Purposeful
Social cues
Embarrassment
Pain
Fear

MRI scans have confirmed that the eyes really do give us an indication of what is happening in someone’s head, literally.

“Duchenne laughter arises in the brainstem and the limbic system (responsible for emotions, whereas non-Duchenne laughter is controlled by the voluntary premotor areas (thought to participate in planning movements) of the frontal cortex.” Giovanni Sabato, Scientific America

Given the established differences between these two forms of laughter, we can pinpoint which one is most beneficial.

Chemical Happiness

We have all heard that laughing can improve our mood. Smiling alone releases serotonin, dopamine, and endorphins. Laughter releases more.

“...regions of the ventromedial prefrontal cortex are activated, releasing endorphins - which are famed for decreasing pain and increasing euphoria.” Medical News Today

Grinning and chucking when the emotion isn’t there still proves useful psychologically. Research has found that smiling or watching comedy, even when we do not feel happy at the time, elevates our mood. One such study asked participants to prop up the sides of their mouths with chopsticks. They still felt happier even when the muscles were moved into a smiling position for them. This provides supportive evidence that non Duchenne smiles have a positive effect on our emotional state. [Kraft, Pressman]

Heart Healthy

Unlike Non-Duchenne laughter, its genuine counterpart benefits our cardiovascular system. A recent study from the University of Maryland has linked laughing in merriment to blood vessel function, specifically the lining of all blood vessels called the endothelium. This special tissue resembles cellophane and also lies beneath chambers of the heart, known as the endocardium. It holds an extremely important role in our cardiovascular health.

Some of the most important responsibilities of the endothelium include:

Development and repair of vessels
Blood coagulation adjustment
Constriction and dilation of vessels (regulating blood pressure)
Inflammatory response
Immune response

Stress Relief

By nourishing the endothelium, the vessels dilate, blood pressure drops, and heart rate reduces. Your oxygen level increases as you breathe deeper. This can create a powerful effect, relaxing physical tension.

Don’t forget, the feel-good hormones are pumping too, easing worrisome and anxious feelings.

Laugh More to Live Longer

A Norwegian study spanning 15 years discovered that having a sense of humor significantly lengthens the human lifespan, especially in women.

“[In women] high scores on humor's cognitive component were associated with 48 percent less risk of death from all causes, a 73 percent lower risk of death from heart disease and an 83 percent lower risk of death from infection. In men, a link was found only for the risk of death from infection—those with high humor scores had a 74 percent reduced risk.” Tori Rodriguez, Scientific American

No doubt, the effect Duchenne laughter has on our body is extraordinary. This is quite possibly the most enjoyable prescription available to improve your physical wellbeing. Enjoy your time with friends and family. Netflix and chill with a comedy. Tell a few jokes. Read the comic strip in your local newspaper. And most importantly, don’t forget to laugh out loud with vigor. After all, it’s good for your health!

Resources:

Dunbar, R I M et al. “Social laughter is correlated with an elevated pain threshold.” Proceedings. Biological sciences vol. 279,1731 (2012): 1161-7. doi:10.1098/rspb.2011.1373

Keltner, Bonanno. “A study of laughter and dissociation: distinct correlates of laughter and smiling during bereavement.” J Pers Soc Psychol. 73, 4 (1997): 687–702.

Kirsch, Daniel L. Stress in Health and Disease, An Issue of Psychiatric Clinics of North America, E-Book. Elsevier, 2014.

Kraft, Pressman. “Grin and Bear It! Smiling Facilitates Stress Recovery.” Association for Psychological Science - APS, 2012.

Miller, Michael, and William F Fry. “The effect of mirthful laughter on the human cardiovascular system.” Medical hypotheses vol. 73,5 (2009): 636-9. doi:10.1016/j.mehy.2009.02.044

Rodriguez, Tori. "Laugh Lots, Live Longer" in SA Mind 27, 5, 17 (September 2016)

doi:10.1038/scientificamericanmind0916-17b

Wattendorf, Westermann, Fiedler, Kaza, Lotze, Celio, “Exploration of the Neural Correlates of Ticklish Laughter by Functional Magnetic Resonance Imaging.” Cerebral Cortex, Volume 23, 6 (2013): 1280–1289.