Everyone likes a good belly laugh from time to time, and science supports that feeling.
Studies have shown that laughing is linked to our physical, emotional and mental well-being — even our relationships.
Here are some things you might not know about laughter.
Laughter was a survival tool
Laughter is thought to have evolved as a form of social bonding in animals and as a way to express playful intention. Many mammals laugh when they are tickled and when they engage in physical play.
But humans don’t need a physical trigger to laugh — though generally we can’t help but laugh if we’re tickled.
Janet Gibson, a professor emerita of cognitive psychology at Grinnell College in Iowa, said that laughter evolved in humans as a communication signal.
Hundreds of years ago, “laughter was the glue that kept the group together,” she told CNN Chief Medical Correspondent Dr. Sanjay Gupta on his Chasing Life podcast.
“The idea was that laughter was an external signal that can tell the group everything is OK, we can relax. (There is) no need to be anxious or threatened by what’s happening around us. And so this would really be a great survival tool for groups of humans,” she explained.
“And the belief is, is that over the centuries, the brain kept these connections so that we now laugh when … we hear things that are relaxing, funny, surprising, amusing.”
Anthropologists think that laughter is universal, but that doesn’t mean every culture finds the same things funny.
Laughing is a primitive noise
Laughter is a surprisingly complicated process, engaging multiple regions of the brain and the body.
The frontal lobe is thought to help you interpret the various bits of information you receive — the sounds and images — and then it decides whether they are funny. That triggers an emotional response in the limbic system, which controls feelings like pleasure and fear and that in turn stimulates your motor cortex, explained Gupta in the podcast.
This controls your physical response — the guffaws, snorts and chuckles we recognize as laughter.
“When you start to laugh you get a fairly large contraction in the rib cage — very large and very fast. Those contractions push air — ha, ha, ha. It’s a very primitive way of making noise. At the brain level, it’s associated with a change in the circulating endorphins,” said Sophie Scott, a professor of cognitive neuroscience at University College London.
This can give you a pain-killing sensation. As you laugh, it lowers your adrenaline levels and over a longer time frame your levels of the stress hormone cortisol, she explained. As such, laughter can improve your mood and make your physical and emotional response to stress less intense.
“You’re more relaxed, less stressed, and you have a pleasant buzzy feeling,” she said.
Couples who laugh together stay together
A long-running study of couples at the University of California, Berkeley, of more than 150 long-term relationships that started in 1989 has suggested that laughter is the glue that keeps people together.
Satisfied couples laugh more than unsatisfied ones, found the study team, led by Robert Levenson, professor of psychology. In one experiment, the couples were asked to discuss a problem or conflict in their relationship while they were videotaped, and a polygraph measured different physiological and emotional signs.
Laughter during the stressful conversation was associated with emotions becoming more positive.
“You see people starting to get stressed, and what you find is that couples who deal with increased feeling of stress, the ones who react to that with laughter not only get less stressed immediately but they are couples that tend to be happier in their relationships and tend to stay together longer,” said Scott, who was not involved in the study.
“It’s not that the laughter is magic dust. It’s more like laughter is a sign of a relationship where people can use laughter to negotiate a better way together,” she added.
In defusing tense situations, she said that laughter can make it easier for couples to communicate and maintain relationship bonds — important planks of relationship satisfaction.
It’s very hard to explain why something is funny
While psychologists and comedians have tried to come up with one, there is no universal theory for what makes something funny.
People sometimes find amusement in the misfortunes of others, in the expression of otherwise forbidden emotions, or in violating a norm but in a nonthreatening way, Scott said.
But sometimes sounds or words can just be inherently funny.
“Any theory of humor always falls down because we can’t explain all the things that are funny, and it can’t be used to generate jokes. Laughter is a really important part of play, and maybe that’s where a lot of adult human play behavior goes, it feeds into humor.”
Laughter can also have a dark side.
Inappropriate laughter can sometimes be a sign that something is cognitively amiss. An early sign of dementia is an altered sense of humor and laughing at inappropriate moments, one study found.
What’s more, laughter doesn’t always accompany genuinely felt emotions — it can also be for social display. People will use laughter to defuse a stressful situation or a joke to break the ice. However, whether it works or not depends on whether the other person joins in and laughs with you, as anyone who has had a punch line fall flat knows.
“When you have endorphins circulating through the brain, you feel good. When you laugh, you’re inhaling more oxygen. So, all the cells of your brain are getting more oxygen, as well as the cells of your body,” Gibson said.
“It’s just a tool in your medicine cabinet to help you feel better. And I’d say it’s free, and it brings in all these other benefits that it’s a great tool to use and not to be dismissed as silly or worthless. “
It’s hard to separate the benefits of laughter and the context in which you would laugh. As such, if you want to harness the healing power of laughter, a funny movie might help — but it’s really the connections laughter builds with other people that count.
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Laughter is a surprisingly complicated process, engaging multiple regions of the brain and the body.
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2021 is already shaping up to be a hot year, with warmer than average spring temperatures and hot streaks across much of the continental U.S into June. In May 2021, there were 947 record warm daily high temperatures recorded across the U.S., according to the National Oceanic and Atmospheric Administration (NOAA). Stackerscoured scientific studies, DIY websites, and even American history to come up with 15 ways to stay cool on warm days without AC.
For anyone not living along the northern edges or mountains of the U.S., the dog days of summer feature weeks—if not months—on end of intolerable heat. Sizzling temperatures have been shown to negatively affect memory, reaction time, productivity, moods, and even suicide rates. One study by Harvard University in 2016 tracked students before and after a heatwave and determined that higher temperatures correlated with decreased cognitive function; another by Stanford University in 2018 studied the links between suicide rates and temperature and ultimately theorized that bumps in temperature from now through the year 2050 may correlate with an added 21,000 deaths from suicide.
For the times we can't be in air conditioning 24/7, there are thankfully many low-cost, energy-efficient ways to cool off during summer heat that work and don't involve sitting in a bath of ice water all day. These tricks can make a difference when your attention is required in a classroom or office setting, or if you're working outside and need relief from the hot sun.
Keep reading to see a simple hack for using skin care products to bring down your core temperature, how hot beverages may actually cool you off, and how to up your use of fans to beat the heat this summer.
Despite one's best efforts to reapply sunscreen as directed, being out in the sun all day can still lead to sunburn and skin damage. The medicinal use of aloe vera to help treat skin ailments can be tracked all the way back to the 4th century B.C. The antiseptic aloe vera is ultimately a wonder plant: In skin care applications it acts as a cleanser, astringent, and moisturizer, and it can stimulate the growth of new skin tissue, while also calming the nervous system. For an extra cooling effect, mix water and aloe vera in ice cube trays, and pop them into the freezer for use when needed.
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Whether your skincare routine involves multiple products or just one, keeping them in the refrigerator can make for a refreshing reprieve from the heat. Many lotions, serums, sprays, and masks will even keep their potency for longer when kept cold.
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There is no better way to heat up a home in the summer than by switching on the oven, burners, or toaster oven. Avoid that entirely by grilling outside, eating out, or switching things up with meals that don't require the stove on the hottest days. Salads, cold sandwiches, cold soups like gazpacho, and nori rolls are all great options for hot days.
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A well-placed bandana that's been soaked in cold water will work wonders to cool you off. Be sure to tie it around a major pressure point (ankles, wrists, neck, or elbows) and it can provide an instant chill.
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Strategic placement of fans throughout the home can completely change an indoor climate. Window fans pulling in cooler outside air should be positioned on the first floor of the shadiest, coolest side of the home (most likely in a north-facing window). A fan blowing out the window, which will suck warmer air from inside, should be placed on the sunniest, hottest side of the second floor (or same floor if it's a one-story home or apartment). Ceiling fans should be rotating counter-clockwise (from your vantage point below it)—don't forget to reverse this direction during cooler months!
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Besides keeping your body hydrated, drinking water helps regulate internal temperatures. Keep your hydration levels topped off throughout the day and evening to ensure heat is being managed most effectively by your most powerful weapon. The American Heart Association recommends drinking water in equal measure to how many ounces of sweat you're expelling—for a high school football player, that can be up to five pounds in one summer practice, or 80 ounces.
Hot water bottles are built to keep people warm on cold nights, but they can also serve the opposite purpose. Fill your hot water bottle (or a regular water bottle, if that's what you have) with tap water, put it in the freezer for a few hours, and then sleep with the bottle at your feet. Your feet are one of the most temperature-sensitive parts of your body, so keeping them cool will help the rest of your body stay cool.
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While a west-facing home may be perfect in winter, it makes cooling the house down in the summer a bit more challenging. Stock up on reusable UV window film to keep the sun's harmful rays out and the cool air in (it will also work to keep your home warm in the winter). Tinfoil and space blankets work great for blocking heat from windows, too, and may save you a few bucks.
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Cotton is a great fabric for the summer whether you live in the dry heat of Arizona or humid Florida; this light material allows air to circulate without getting trapped in one place, cooling your body naturally. Other fabrics that can help you fight off the sweat are chambray, rayon, linen, and synthetic blends, and lighter colors are generally cooler than darker colors.
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Drinking a lot of water is one way to stay hydrated during the summer, but it can also be done through eating foods that have high water content. This includes fruits and vegetables such as melons, cucumbers, lemons, grapes, leafy greens, and berries. Spicy foods prepared with chili peppers are great coolers as well: the chilis increase circulation and cause perspiration. And while ice cream might seem refreshing in the moment, it will only make you feel warmer in the long run—flavored ice is a good alternative.
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It seems counterintuitive, but drinking something hot on a warm, dry day can help to cool a body off. A Thermal Ergonomics Lab study found that drinking a hot beverage increases sweat production, which in turn cools the body off. There's just one caveat—the sweat needs to be able to evaporate in short order. This trick will not work if you're wearing a lot of clothing that can trap sweat or if the scorching day is paired with high humidity.
Strategically opening windows at night when the air is coolest and keeping them closed (with curtains drawn!) during the day is one of the most straightforward ways to keep a home cooler in summer months. This method is most effective if you have adequate insulation in the walls to trap the cooler night air inside. Another window trick is to take advantage of convection: When double-hung windows are open, keep them as such at the top and the bottom. Having the top window cracked allows hot air to escape, while the bottom window being cracked will suck in cooler air from outside.
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Plan ahead for hot nights: fold up a top sheet, put it in a bag, and set said bag in the freezer a few hours before bed. When it's time to hit the hay, take the sheet out and lay it on top of you. For a last-minute (slightly messier) iteration of the same technique, before going to bed wet down a top sheet in cold water, wring the sheet out well, and put it over yourself.
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In addition to keeping windows closed during the day and open at night, use blackout curtains to trap cool air inside and keep the heat from coming in. They've been said to reduce heat transfer through windows by as much as 24%—that's a lot of degrees when it's sweltering outside.
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Pranayama is the practice of breath control—and utilizing it can make you feel noticeably cooler. Two breaths, in particular, that can help are the sitali (“cooling breath”) and sitkari (“sipping” or “hissing”). In the sitali, the mouth is opened into an “O,” and the tongue folded lengthwise into a tube to suck air through. After sticking the curled tongue out almost an inch from the lips, a big breath is drawn in, using the tongue like a drinking straw. This will pull cool air into the diaphragm. After breathing in, the mouth is closed and air slowly exhaled through the nose. The sitkari variation of this breath involves closing the top and bottom teeth together with lips open in a smile. Long, slow breaths are drawn in this position through the teeth and mouth, then the mouth is closed and the breath exhaled slowly through the nose.
