Why Do We Laugh? The Science Behind Laughing, According to Experts

There's way more to our giggles and guffaws than simply thinking something is funny. We asked a laughter expert to explain.

No vocalization is more universal (or unifying) than laughter. There are no language or cultural barriers—everyone everywhere understands the concept—and there’s no learning curve. “Babies don’t need to have seen or heard laughter to know how to do it,” says Sophie Scott, PhD, a professor of cognitive neuroscience at University College London and one of the world’s leading experts on laughter. But why do we laugh?

According to scientific studies, it’s not just funny one-liners, funny words, funny photos or funny movies that elicit chuckles. In fact, humor isn’t even the main reason we laugh. Curious about the cause of our giggles and guffaws, we asked Scott to explain the science behind laughter, including the health benefits. This is guaranteed to make you want to laugh more every day.

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What is laughter?

“Laughter is a nonverbal emotional expression,” Scott explains. “The emotion that we seem to be expressing with it is joy, but it’s a social joy that is primarily experienced with other people.”

The community aspect of joy is paramount to understanding the reasons we laugh. While people certainly can (and do) laugh when they are alone, they’re much less likely to than when they’re around other people. According to a scientific paper published in Trends in Cognitive Sciences, people are 30 times more likely to laugh if they are with someone else than if they are alone.

But it’s not something we do intentionally, at least not when it comes to the sort of genuine laughter that bubbles out of us. What’s more, there are times when we can’t help but laugh (and can’t stop), such as if we’re being tickled.

So what exactly is happening in the body when we laugh? Scott explains that laughter is a physiological response. When we laugh, the brain releases endorphins, which relax the whole body. Our facial muscles and respiratory system are both involved in laughter.

In other words, we’re hardwired for laughter. Everyone has the ability to laugh, even blind babies who have never seen laughter and deaf babies who have never heard it. Other mammals laugh too, including rats when they are tickled. “It’s likely that many species of animals laugh and we just don’t realize it because we don’t know what their laughter sounds like,” Scott says.

Why do we laugh?

Lovely little girl smiling at the camera while playing on a swing set in playground joyfullyTang Ming Tung/Getty Images

Sure, you’ll snicker at silly dad jokes and funny pickup lines, but contrary to what many believe, finding something funny is not the only cause—or even the main cause—of those chuckles. So why do we laugh? There are four primary reasons, and they relate to our need for social connections, our desire to cloak our emotions, our uncontrollable bodily responses and, of course, our sense of humor.

For social connection

Scott points to social connection as the main driver of laughter. Yes, this plays an even bigger part in your belly laughs than hilarious jokes or funny songs.

“Most laughter happens as part of social interactions,” she says. Scientific research supports that. Remember the findings of the Trends in Cognitive Sciences paper? We’re 30 times more likely to laugh if we’re with someone else than if we’re alone. Another study found that people who don’t have many social relationships and live alone laugh less than those who have more social relationships and don’t live alone.

To mask our emotions

People don’t just laugh to express joy. Scott says that sometimes we laugh to mask other emotions. Feeling anger, anxiety or fear can lead to laughter (hence the term nervous laughter). Whether consciously or not, we may use laughter to manage these difficult emotions.

It’s a bodily response

Some people laugh as a response to bodily stimulation—namely, tickling. Scientists still don’t know exactly why tickling leads to laughter, but they do know it’s uncontrollable and involves the hypothalamus, the area of the brain that controls mood (along with body temperature, hunger and heart rate); the parietal operculum, an area involved in sensory, motor, autonomic and cognitive processing; the amygdala, where emotions are processed; and the right cerebellum, which is associated with language.

We find something humorous

It may not be the No. 1 reason we cackle uncontrollably, but finding something funny does make us laugh. Consider comedy movies. Many people find watching someone fall, an essential element of slapstick comedy, particularly humorous. Why do we laugh at this? According to a scientific paper published in Neuropsychologia, the facial expressions of the afflicted can cause us to laugh. When someone falls and looks bewildered, we find this funny.

Is laughter contagious?

Cheerful young friends laughing while sitting on sofa during partyThe Good Brigade/Getty Images

Chances are, you’ve been here: surrounded by friends and watching as laughter falls like dominoes around the group. Pretty soon, you’re all shaking, bellies aching with uncontrollable, unstoppable laughter. And it all started with a single, small snicker.

Yep, laughter is contagious. Scientific studies back this up, showing that laughter is contagious in the same way yawning is; often, it’s uncontrollable.

Scott says that the reason we laugh when we see someone else laughing has to do with laughter as a form of social bonding. It’s a way to demonstrate affection and (at least most of the time) shared joy. Social bonds are so critical to the human species that, sometimes, we don’t even realize we’re laughing as a way to connect with others.

Why do we cry when we laugh?

Just like laughter, the tears we produce when we’re laughing are uncontrollable.

When something has us in stitches—a witty dark joke, say—we’ll often find ourselves tearing up. This uncontrollable response is particularly interesting: We generally view laughing as an expression of a positive emotion and crying as an expression of sadness.

“Science doesn’t have a clear answer on why some people cry when they laugh,” Scott says. “One hypothesis is that people produce tears when they’re feeling helpless, and the tears are marking that. But it’s just a hypothesis, and it hasn’t been proven.” Either way, don’t be surprised if a sidesplitting episode of your favorite sitcom has you reaching for the tissues for a happy reason.

What are the health benefits of laughing?

Perhaps a better question than “Why do we laugh?” is “What are the benefits of it?” Science is clear that laughter is good for us. But Scott emphasizes that it’s virtually impossible to know if the health benefits stem directly from laughing or from the socialization that typically goes hand in hand with laughter. To her point, numerous studies have shown that social connection is beneficial for health and can even add years to our lives. Bearing this in mind, below are six health benefits linked to laughter.

Laughter relieves stress

“When we laugh, levels of cortisol—known as the stress hormone—go down,” Scott says. “You also get an uptick of adrenaline, and endorphins are released.” This leads us to feel happier and more relaxed. One study even suggests it’s a good add-on to the treatment of stress and depression.

So next time work has your stress levels creeping up (way up), pause to read funny work memes or scroll through humorous social media accounts to get a bit of relief.

It could relieve pain

Studies have shown that laughter is useful for people coping with both physical and emotional pain. Though the research is still young, the connection likely comes back to the fact that laughing releases endorphins.

It probably won’t take your pain from unbearable to zero, but humor could be just the distraction you need to get through a tough time. Give it a go by cueing up your favorite Hulu comedy, or picking up one of the funniest books of all time.

It strengthens relationships

Married couple embracing in front of residential homeMoMo Productions/Getty Images

When University of California psychology professor Robert Levinson invited couples into his lab and asked them to discuss things about their partner that irritated them, he found that the couples who tackled this stressful situation using humor and laughter had higher levels of relationship satisfaction.

On a related note, having the same sense of humor as your partner can strengthen your relationship.

Laughter burns calories

According to a Vanderbilt University study, laughing for 10 to 15 minutes can increase your heart rate and oxygen consumption enough to burn 40 calories. That may pale in comparison to an actual workout, but it’s not too shabby as a side effect of enjoying yourself.

It’s good for your brain

Research from Loma Linda University shows that laughing improves the short-term memory of adults in their 60s and 70s. In a randomized, controlled trial, participants who watched funny videos had 44% better recall ability than participants who were asked to sit quietly—a pretty remarkable difference!

Laughter is good for your heart

Heart disease is nothing to laugh at … or is it? Research suggests laughter may be good for your ticker. In a 2016 study published in the Journal of Epidemiology, University of Tokyo researchers asked people who were 65 years old or older how often they laughed aloud, finding that those who said they almost never laughed had a higher risk for heart disease and stroke than those who laughed daily, who may have been protected by laughter’s ability to reduce stress.

Laughter is the best medicine

Considering the many and varied benefits of laughter, you may be wondering whether smiling can be just as rewarding. Science does show there are benefits to smiling—it can create social bonds, for example. But it won’t make you feel happier or relaxed the way laughter can. Since it takes less effort to smile, it likely has fewer cardiovascular benefits and burns fewer calories as well.

So next time you feel the urge to laugh burbling up, don’t hold back. And if you need something to get the giggles going, consider spending time with people who bring you joy. It just might add years to your life!


  • Sophie Scott, PhD, professor of cognitive neuroscience at University College London
  • Trends in Cognitive Sciences: “The social life of laughter”
  • BMJ Open: “Impact of social relationships on income-laughter relationships among older people: the JAGES cross-sectional study”
  • Cerebral Cortex: “Exploration of the neural correlates of tickling laughter by functional magnetic reasoning imaging”
  • Neuropsychologia: “Why do we laugh at misfortunes? An electrophysiological exploration of comic situation processing”
  • Frontiers in Psychology: “Hearing Someone Laugh and Seeing Someone Yawn: Modality-Specific Contagion of Laughter and Yawning in the Absence of Others”
  • PNAS: “Social relationships and physiological determinants of longevity across the human life span”
  • European Journal of Pain: “Laughing away the pain: a narrative review of humour, sense of humour, and pain”
  • International Journal of Obesity: “Energy expenditure of genuine laughter”
  • Advances in Mind-Body Medicine: “The effect of humor on short-term memory in older adults: a new component for whole-person wellness”
  • Journal of Epidemiology: “Laughter is the Best Medicine? A Cross-Sectional Study of Cardiovascular Disease Among Older Japanese Adults”

Emily Laurence
Emily Laurence is a journalist and certified health coach living in Raleigh, North Carolina, with 15 years of experience writing about entertainment, health, lifestyle and social justice. She has worked for Seventeen magazine, Well+Good and ELLE.com, and she’s written for many publications including Shape, Marie Claire, The Huffington Post and Parade.