11 Scientific Benefits of Having a Laugh

iStock.com/Petar Chernaev
iStock.com/Petar Chernaev

They say that laughter is "the best medicine," and as it turns out, there is some scientific truth to this assertion. Humor-associated laughter has numerous health benefits, so here are 11 reasons you should laugh it up.

1. Laughter is a sign of good will toward others.

Group of friends laughing in a restaurant
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Laughter may be unique to humans. Why do we do it? According to a 2010 study in BMC Complementary and Alternative Medicine, laughter and smiling are generally intended as a message of good will. The authors extrapolate that there is a similar function in primates, who use facial expressions with bared teeth to suggest friendliness and sociability. They write, "Because some forms of smiling are voluntary and easily faked, laughter, which requires a more synergetic contraction of the wider musculature, is believed to have evolved in humans to express a secure, safe message to others."

2. Laughter may reduce your blood pressure.

Two girls laughing in a car
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High blood pressure (hypertension) is one of the most dangerous side effects of stress, as well as a huge risk factor for heart disease and stroke. However, it's hard to be stressed when you're laughing, so researchers have investigated whether laughter can bring blood pressure down. There are more than a few studies that show a reduction of blood pressure after laughter, such as a 2017 study in the Journal of Dental and Medical Research, where 40 patients undergoing hemodialysis listened to CDs of comic shows for 16 30-minute sessions over eight weeks, and saw a decrease in blood pressure.

In 2011 researchers presented results of a three-month-long study at the American Heart Association's Scientific Sessions. Researchers exposed 79 participants to either a music or laughter therapy. Laughter was stimulated through "playful eye contact" and breathing exercises. Immediately after sessions, the blood pressure readings from the laughers lowered by 7 mmHg—(millimeters of mercury, how the blood pressure readings on a sphygmomanometer are abbreviated). In comparison, music therapy only brought blood pressure down by 6 mmHg.

After three months, the blood pressure readings significantly decreased overall by 5 mmHg among the laughers. People in the comparison group showed no change in blood pressure readings.

3. This had led to a treatment known as laughter yoga.

group laughing in a workout class
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The success of laughter studies on blood pressure and other ills has led to a unique kind of treatment known as "laughter yoga."

Dr. Madan Kataria, founder of the Laughter Yoga School, told Medscape, "You don't need any jokes, any humor, or any comedy. You don't even need to be happy. What we do is laugh in a group and initiate laughter as a form of bodily exercise, but when we have eye contact with others, this laughter becomes real and contagious."

Kataria led a study of 200 male and female individuals who participated in laughter yoga sessions for 20 to 30 minutes. The researchers stimulated laughter in the participants for between 45 seconds and one minute, followed by deep breathing and stretching for the duration of the sessions.

Subjects who laughed saw a reduction in their systolic blood pressure of more than 6 mmHg, a significant change from baseline and also significant when compared with a non-laughing control group. Diastolic blood pressure was also significantly reduced. In addition, their levels of cortisol, a stress hormone, were also reduced.

As a result, laughter yoga has gone on to be used as an intervention for a variety of health issues, ranging from stress to dementia.

4. Laughter can reduce anxiety and other negative emotions.

Two guys laughing and shaking hands
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A 1990 study in Psychological Reports looked at the effects of humorous laughter on threat-induced anxiety. Researchers led 53 college students to believe (falsely) that they were going to receive an electric shock after a waiting period.

Subjects in the experiment group listened to a humorous tape while waiting for their shock. The placebo group listened to a non-humorous tape, and the control group did not listen to any tape. The humor group reported that their anxiety decreased during the anticipatory period, and those with the highest self-reported level of sense of humor had the lowest reported anxiety.

Laughter therapy has also been shown to improve anxiety in patients with Parkinson's disease [PDF], reduce anxiety and depression in nursing students, and improve optimism, self-esteem, and depression in menopausal women.

From a general psychological perspective, author Bernard Saper suggests in a paper for Psychiatric Quarterly that the ability to maintain a sense of humor and the ability to laugh can act as positive coping mechanisms to help a person get through difficult times.

5. Laughter is an immune booster.

Mom and boy laughing on couch
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At the beginning of cold and flu season, it may be a good idea to practice some laughter therapy, as several studies have shown the immune boosting power of a chuckle.

In one 2015 study on postpartum mothers in the Journal of Alternative and Complementary Medicine, researchers tested hand-expressed breast milk for immunoglobulin (IgA, antibodies that play an important role in immune function) before and after laughter therapy.

Twice a week, participants engaged in group "laughter dance routines" and some light breast massage while inducing laughter. Mothers who participated in the laughter therapy saw a small increase in their IgA. However, even a small amount was significant to the researchers, given that the postpartum period is when natural IgA in breast milk declines (it is at its highest level right after delivery, in the earliest, nutrient-dense breast milk known as colostrum).

Another study with college students found that watching funny movies increases salivary IgA (sIgA). Researchers have also found small examples of laughter's ability to increase the body's natural killer cells (NKs), a type of lymphocyte that is easy to test for in the blood. One study in the American Journal of Medical Science, albeit small—a cohort of only 10 male subjects—found significantly increased NK cell activity in the experimental group. Additional studies have shown increases in NK cell activity after laughter therapy or humorous videos, but most of these studies were done on male subjects.

6. Laughter may act as a natural anti-depressant.

woman laughing with dog
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While nobody would recommend laughter in lieu of other treatment for depression, it has shown promise at ameliorating depressed moods. Patients in long-term care facilities often suffer from depression and poor sleep, so a 2017 study in the Korean Journal of Adult Nursing [PDF] tested the effects of laughter therapy on 42 residents of two long-term care hospitals. The results were promising.

The laugher therapy, which the subjects undertook over eight sessions, for 40 minutes twice a week, included "singing funny songs, laughing for diversion, stretching, playing with hands and dance routines, laughing exercises, healthy clapping, and laughing aloud."

The results showed reduced depression and general mood improvement as well as improved sleep in the experiment group compared to the control group.

Another 2015 study in the Journal of Alternative and Complementary Medicine found that three 60-minute laughter therapy sessions improved the depression and negative mood states of cancer patients.

7. You breathe better after laughing.

grandfather and grandson laughing on ground
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It turns out that a good bout of deep belly laughter can lead to increased heart rate, respiratory rate, and oxygen consumption, which are similar to what happens during exercise. While a 2009 study in the International Journal of Humor Research found that these changes only last as long as the laughter itself, if you can laugh like that for 30 minutes to an hour, maybe you can skip the gym.

8. Laughter is good for your cardiovascular system.

women laughing at a movie
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Your lungs aren't the only organ that benefits from a great guffaw. A 2009 study in Medical Hypotheses found powerful benefits to the heart and cardiovascular system.

Study participants watched either a comedy like Saturday Night Live or the bleak opening sequence of Saving Private Ryan, which is known to increase mental stress. They used a technique called brachial artery reactivity testing (BART), a form of ultrasound that looks at the brachial artery. Participants who watched the stressful movie experienced a 35 percent reduction in flow-mediated vasodilation (FMD, or how blood vessels dilate and contract); sluggish FMD is a risk factor for atherosclerosis. Meanwhile, the group that watched the funny scene saw a 22 percent increase in FMD, comparable to exercise. In short, laughing helped their blood flow better.

The American Heart Association recommends laughter for a healthy heart, adding that research has shown laughter promotes reduced artery inflammation and increased production of HDL, or "good" cholesterol.

9. Laughter calms stress hormones.

man and woman laughing
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Humor, and by extension, laughter, stimulates multiple physiological systems that decrease levels of stress hormones, such as cortisol and epinephrine, and increase the activation of the dopamine-dispensing reward system of the brain, according to researchers of a 2017 study in Advances in Physiology Education. A 2003 study in Alternative Therapies in Health and Medicine found that viewing a funny film decreased a wide variety of stress hormones.

10. Social laughter can relieve pain.

Girl with broken arm laughing in doctor office
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Laughter might be as good as some analgesics for pain, something early physicians seemed to understand. In the 14th century, French surgeon Henri de Mondeville used humor to distract patients from the pain of surgery and to help them during recovery.

More modern research has found that participants who watched comedy videos needed less pain medication than those who watched control videos. In a 2011 study published in the Proceedings of the Royal Society, over the course of six experiments using extreme cold as a pain-tolerance measure, researchers found that social laughter—laughter done in groups in a social context—elevates pain thresholds. The authors suggest, "These results can best be explained by the action of endorphins released by laughter."

11. Laughing burns calories.

Woman laughing on a running trail.
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As if all of these benefits aren't a good enough reason to giggle every day, a 2014 study in the International Journal of Obesity found that laughter can burn calories. Researchers broke a group of 45 participants into two groups, half of whom watched film clips intended to evoke laughter for approximately 10 minutes, and half who watched film clips unlikely to stimulate laughter. Both groups were attached to a "calorimeter" that measured energy expenditure and heart rate. They determined that those who laughed during their viewing burned up to 10 calories in 10 minutes, as compared to those who did not laugh and did not burn any calories.

The Best Place to Park at the Mall, According to Science

Diy13/iStock via Getty Images Plus
Diy13/iStock via Getty Images Plus

It’s Black Friday, and you are entering the battlefield: a mall parking lot. You’re determined to nail that doorbuster deal, and quantities are limited. The field is already full of other combatants. You must find the perfect parking spot.

Do you grab the first one you see, or drive as close to the mall as you can and hover? Or, do you choose a tactic that lies somewhere between?

Parking at the mall has long frustrated drivers and taxed the minds of traffic engineers—but after working on the problem for three years, physicists Sidney Redner of the Santa Fe Institute and Paul Krapivsky of Boston University have gotten closer to a winning strategy. “There are lots of studies of parking lots, but it’s just that they’re so complicated, you don’t get any insight into what’s actually happening,” Redner tells Mental Floss.

Redner and Krapivsky, whose work employs statistical physics to make sense of large systems, simplified the messy dynamics of a parking lot by modeling it with a one-dimensional grid of cells, each representing a parking space. They tested three simple, yet realistic, parking strategies using basic probability theory. Their model tested the following strategies to see which one resulted in least time spent walking and driving in the parking lot:

Meek Strategy: Meek drivers park in the first open space they see, however distant it is from the mall. As a result, they often spend the most time walking to and from the mall.

Prudent Strategy: Prudent drivers look for the first open spot but then keep driving toward the mall. They continue to drive until they see a parked car and then park in the best open spot between that first open spot and that first parked car. There may be a block of open spaces between the first open space and the first parked car. From that block of open spaces, they choose the one closest to the mall.

Optimistic Strategy: Optimistic drivers drive as close to the mall as possible and look for a parking space close to the entrance. If they see one, they grab it. If there are none, they backtrack and choose the first open space they see. Optimistic drivers probably spend the most time driving and the least time walking. In the worst-case scenario, they end up parking back where a meek driver would have parked.

Naturally cautious drivers are more likely to default to the meek mode, while aggressive drivers often use the optimistic strategy, well, aggressively. And most drivers have tried something like the prudent method.

So, which is your best bet in a crowded mall parking lot this holiday season?

In the experiments, the prudent strategy fared best, followed closely by the optimistic strategy. The meek strategy finished a distant third (“It’s hard to comprehend just how bad it is,” says Krapivsky, a self-described meek driver).

And even better: The more crowded the lot, the better the prudent strategy works, he adds.

One clear takeaway from the study is that meek drivers may want to ramp up their parking skills before going to the mall. “You don't want to park on the very outskirts of the lot, like a mile away from the stores. You want to go to the first place there’s an open spot and park somewhere in that first open area,” Redner says. They published their findings in the Journal of Statistical Mechanics [PDF].

The researchers say this is the best of the strategies they tested, but it has its limitations. It does not take into consideration competition among a sea of drivers all looking for parking spaces at the same time, and it doesn’t include (perhaps optimistically) the psychological aspects of operating a vehicle. “We are not rational when we are driving,” Krapivsky tells Mental Floss.

The researchers’ one-dimensional grid model also assumed that there would be one car at a time entering the lot through one entrance, unlike messier lots in the real world, where many cars enter from a multitude of entrances.

The optimal parking strategy, one that would best all others every time, has yet to be found. In their research, though, Redner and Krapivsky are homing in on one that integrates the more complicated aspects of parking.

For now, science says prudence is a virtue in the parking lot. And while the meek might inherit the Earth, they certainly won’t find the best parking space at the mall.

'Lost Species' of Tiny, Rabbit-Sized Deer Photographed in Vietnam for the First Time in 30 Years

Global Wildlife Conservation
Global Wildlife Conservation

The silver-backed chevrotain, also called the Vietnamese mouse-deer, is elusive. It's so elusive that scientists had feared it was extinct after none had been photographed for decades. But as The Washington Post reports, the first images taken of the mammal in nearly 30 years prove that the species is still alive in the woods of Vietnam.

No larger than small dogs, chevrotains are the tiniest ungulates, or hoofed animals, on Earth. They have vampire-like fangs and skinny legs that support their bodies. Silver-backed chevrotains are characterized by the silver sheen of their tawny coat.

The tiny population native to Vietnam has been devastated by poachers in recent decades. That, and the animal's natural shyness, make it incredibly difficult to study. Before this most recent sighting, the last time scientists had recorded one was in 1990.

Global Wildlife Conservation, the Southern Institute of Ecology, and the Leibniz Institute for Zoo and Wildlife Research teamed up in hopes of documenting the lost species. Researchers interviewed residents and government forest rangers in the Vietnamese city of Nha Trang about the silver-backed chevrotain, looking for tips on where to find one. Residents said that while populations had been hit hard by hunting, the animals were still around.

Based on this local ecological knowledge, scientists set up three camera traps in the Vietnamese woods. In just five months, they captured 275 photographs of the little mouse-deer. They then installed 29 additional cameras and snapped 1881 new images in that same length of time.

“For so long this species has seemingly only existed as part of our imagination," Global Wildlife Conservation associate conservation scientist An Nguyen said in a statement. "Discovering that it is, indeed, still out there, is the first step in ensuring we don’t lose it again, and we’re moving quickly now to figure out how best to protect it.”

Now that a silver-backed chevrotain population has been located, researchers plan to conduct the first-ever comprehensive survey of the species. Once the data is collected, it will be used to build a plan for the species' survival.

[h/t The Washington Post]

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