Why Do Babies Laugh?

A baby's laugh can offer a lot of insight into their development.
A baby's laugh can offer a lot of insight into their development.
aldomurillo/iStock via Getty Images

Humor has always been subjective. Where some people prefer the physical comedy of Jim Carrey, others may find the dry approach of Albert Brooks preferable.

Babies, of course, are not big on subtlety. Making silly faces, tickling their feet, or pretending you’ve disappeared in an endless loop of temporal displacement—otherwise known as peek-a-boo—are all ways to get tiny people to laugh. But why exactly are they laughing? Is it because they find their parents funny, or it is a reflex? Are they processing humor, or is it merely a way of socializing? Is baby laughter a way of saying, “Please continue paying attention to me”?

We asked several babies and got no answers. (In many cases, a loaded diaper ended questioning prematurely.) Fortunately, a number of researchers have explored the topic of what infants find funny in depth. “Almost all babies are laughing by the time they’re 4 months old,” Gina Mireault, a professor of psychology in the behavioral sciences department at Northern Vermont University, tells Mental Floss.

But, Mireault adds, in both adults and babies, “one of the biggest misunderstandings about humor is that it doesn’t have to have anything to do with something being funny.”

From Smiling to Laughing

Early in their lives, babies are nonverbal—they burble and coo incoherent nonsense. Smiling, laughing, and crying are therefore crucial to interacting with the rest of the world. You probably won’t catch a baby laughing all by herself. “It’s a social response,” Mireault says. “The requisite ingredient is another person.”

Babies typically start smiling at 6 to 12 weeks old. At 3 to 4 months, babies will laugh at actions involving physical stimulation, like tickling, raspberries, or being bounced on their caregiver’s knee. (In a 2014 study conducted by developmental psychologist Caspar Addyman at the Goldsmiths InfantLab at the University of London, parents reported that tickling was the top way of getting their child to laugh.) At 5 to 6 months, they’ve learned enough about the world around them to comprehend the basic tenet of humor—a distortion of reality. Once they’ve grasped the appearance of normal human behavior, they’ll giggle at big eyes, blown-out cheeks, and high-pitched voices.

“It tends to involve behavior my colleagues have described as ‘clowning,’” Mireault says. “It could be a giant hat, a big bow tie, unusual voices, or walking in a funny way.” In observing these social rule violations, babies are amused because they have expectations about how people normally behave. You pretending to be a kangaroo is not what they anticipate.

“Surprise is one of the key elements of humor,” Mireault says. “There are two theories. One is called the Arousal-Safety hypothesis, and another is called the Benign Violation Theory. They’re the same thing. The idea is that humor that involves a surprise is perceived as non-threatening.”

If you hand your child a stuffed animal, they will expect the stuffed animal. If you suddenly toss it on the floor, this new development will probably cause them to laugh. The key is familiarity and a sense of playfulness. A smiling adult tossing it aside will be funny. A stranger angrily throwing it against a wall will not. Even Charles Darwin made note of this, writing in his 1872 work, The Expression of the Emotions in Man and Animals, that being tickled by a stranger would prompt a child to “scream in fear.”

There are exceptions. In London, children’s theater producers Sarah Argent and Kevin Lewis have staged several plays aimed at a baby demographic aged 6 months and older with assistance from Caspar Addyman and research from the InfantLab. Plays like Out of the Blue and Shake, Rattle, and Roll anticipated a baby’s natural wariness of strangers. Performer Maisie Whitehead “met” the babies at the start of Shake, Rattle, and Roll, singing to them to get them accustomed to her presence. During the show, Whitehead pretending to “wobble,” losing and regaining her balance, entranced the babies.

What stood out for Lewis was the idea that a baby’s laugh can be a method of control. “There is a sense that laughter is a tool of power,” Lewis tells Mental Floss. “’If I laugh, the big person does this thing or action again. I can keep making them do it again and again and again and again and keep having pleasure and I am in control!’” In laughing, babies are utilizing a form of manipulation.

Why Babies Love Peek-a-Boo

Babies can also pick up on intention. If you pretend to drop something and say “ha, ha,” the baby will probably laugh. But if you say “uh-oh” and seem concerned, the baby will treat it like a serious event. Dropping objects with an exaggerated response was, in fact, a highlight of Argent's productions, sending babies into giggle fits.

There’s an expiration date on such actions, since babies will quickly learn the unexpected action—tossing the stuffed animal—can now be expected. Or, as Mireault puts it: “Babies aren’t stupid. They won’t find it infinitely funny.”

Bust out a game of peek-a-boo and watch your baby get the giggles.Brand X Pictures/iStock via Getty Images

The more babies learn about the world, the more caregivers are able to subvert their expectations. But one misunderstanding is what leads to the closest thing to a guaranteed laugh parents can perform without resorting to the cheap trick of tickling: peek-a-boo.

There are a couple of reasons why it works. One relates to a construct identified by Swiss psychologist Jean Piaget called object permanence, or the idea something that’s out of sight still exists.

To a baby, the existence of a physical object depends on whether it’s visible. “If you hide something from a 6-month-old baby, like car keys, by covering them up, the baby won’t look for them," Mireault says. The idea the keys have been obscured is not a concept they can grasp.

The same holds true for faces. If a parent covers their face with their hands, its sudden reappearance is a delightful surprise. Adds Mireault, “When you pop up again, it’s like, ‘Holy smokes, where did you come from?’”

Peek-a-boo is also a baby pleaser because it involves that distortion of reality—big eyes and silly faces. By 8 or 9 months, however, babies have caught on to object permanence. Now, when a parent leaves the room, the baby might get upset. They know the adult is in another room, as opposed to just having briefly blipped out of existence.

That doesn’t mean peek-a-boo will no longer be effective. They can be amused by the fulfillment of the expectation—that their parent resurfaces—or by hiding themselves. Alternately, a baby may laugh, but as they get older, it may become less sincere. “Babies can fake laugh at 6 months," Mireault says. "They can laugh to get attention. They start to babble and get vocal control and use voluntary laughter. Like when someone says, ‘Ha, ha, ha,’ and it doesn’t sound super genuine. It’s just a nice social gesture.”

It is disturbing to think that an adult considered a comic genius by a baby at 4 months may be a Vegas hack by 6 months, deserving only sympathy chuckles. By laughing, Mireault says, “The infant is saying, ‘Look, this is not that funny anymore, but I don’t want to stop playing, so come up with something else.’”

Babies' Sense of Humor

As babies age into toddlerhood, other kinds of humor begin to make sense. At 7 to 9 months, they find humor in contradictions. Put a hat on a dog and watch them crack up. At 12 months, they may see a cup and call it a spoon or laugh at an adult who does the same thing.

But the real landmark in a baby’s sense of humor may come when they make an attempt to make others laugh. At 5 months, enough motor control has been established so that babies can begin to hold up their own smelly feet rather than wait for a parent to do it. At 8 months, they’ll tease others. “It shows they understand other people can be tricked," Mireault says. "They’ll offer something like car keys and when you reach for them, they’ll pull them away.”

This is more than just humor. It shows a theory of mind, or the idea that other people have different thoughts, beliefs, and expectations. Funny faces may seem simple, but humor is a cognitive puzzle that helps babies grow up—and eventually keep the car keys.

10 of the Best Indoor and Outdoor Heaters on Amazon

Mr. Heater/Amazon
Mr. Heater/Amazon

With the colder months just around the corner, you might want to start thinking about investing in an indoor or outdoor heater. Indoor heaters not only provide a boost of heat for drafty spaces, but they can also be a money-saver, allowing you to actively control the heat based on the rooms you’re using. Outdoor heaters, meanwhile, can help you take advantage of cold-weather activities like camping or tailgating without having to call it quits because your extremities have gone numb. Check out this list of some of Amazon’s highest-rated indoor and outdoor heaters so you can spend less time shivering this winter and more time enjoying what the season has to offer.

Indoor Heaters

1. Lasko Ceramic Portable Heater; $20


This 1500-watt heater from Lasko may only be nine inches tall, but it can heat up to 300 square feet of space. With 11 temperature settings and three quiet settings—for high heat, low heat, and fan only—it’s a dynamic powerhouse that’ll keep you toasty all season long.

Buy it: Amazon

2. Alrocket Oscillating Space Heater; $25


Alrocket’s oscillating space heater is an excellent addition to any desk or nightstand. Using energy-saving ceramic technology, this heater is made of fire-resistant material, and its special “tip-over” safety feature forces it to turn off if it falls over (making it a reliable choice for homes with kids or pets). It’s extremely quiet, too—at only 45 dB, it’s just a touch louder than a whisper. According to one reviewer, this an ideal option for a “very quiet but powerful” heater.

Buy it: Amazon

3. De’Longhi Oil-Filled Radiator Space Heather; $79


If you prefer a space heater with a more old-fashioned vibe, this radiator heater from De’Longhi gives you 2020 technology with a vintage feel. De’Longhi’s heater automatically turns itself on when the temperatures drops below 44°F, and it will also automatically turn itself off if it starts to overheat. Another smart safety feature? The oil system is permanently sealed, so you won’t have to worry about accidental spills.

Buy it: Amazon

4. Aikoper Ceramic Tower Heater; $70


Whether your room needs a little extra warmth or its own heat source, Aikoper’s incredibly precise space heater has got you covered. With a range of 40-95°F, it adjusts by one-degree intervals, giving you the specific level of heat you want. It also has an option for running on an eight-hour timer, ensuring that it will only run when you need it.

Buy it: Amazon

5. Isiler Space Heater; $37


For a space heater that adds a fun pop of color to any room, check out this yellow unit from Isiler. Made from fire-resistant ceramic, Isiler’s heater can start warming up a space within seconds. It’s positioned on a triangular stand that creates an optimal angle for hot air to start circulating, rendering it so effective that, as one reviewer put it, “This heater needs to say ‘mighty’ in its description.”

Buy it: Amazon

Outdoor Heaters

6. Mr. Heater Portable Buddy; $104

Mr. Heater/Amazon

Make outdoor activities like camping and grilling last longer with Mr. Heater’s indoor/outdoor portable heater. This heater can connect to a propane tank or to a disposable cylinder, allowing you to keep it in one place or take it on the go. With such a versatile range of uses, this heater will—true to its name—become your best buddy when the temperature starts to drop.

Buy it: Amazon

7. Hiland Pyramid Patio Propane Heater; Various


The cold’s got nothing on this powerful outdoor heater. Hiland’s patio heater has a whopping 40,000 BTU output, which runs for eight to 10 hours on high heat. Simply open the heater’s bottom door to insert a propane tank, power it on, and sit back to let it warm up your backyard. The bright, contained flame from the propane doubles as an outdoor light.

Buy it: Amazon

8. Solo Stove Bonfire Pit; $345

Solo Stove/Amazon

This one is a slight cheat since it’s a bonfire pit and not a traditional outdoor heater, but the Solo Stove has a 4.7-star rating on Amazon for a reason. Everything about this portable fire pit is meticulously crafted to maximize airflow while it's lit, from its double-wall construction to its bottom air vents. These features all work together to help the logs burn more completely while emitting far less smoke than other pits. It’s the best choice for anyone who wants both warmth and ambiance on their patio.

Buy it: Amazon

9. Dr. Infrared Garage Shop Heater; $119

Dr. Infrared/Amazon

You’ll be able to use your garage or basement workshop all season long with this durable heater from Dr. Infrared. It’s unique in that it includes a built-in fan to keep warm air flowing—something that’s especially handy if you need to work without wearing gloves. The fan is overlaid with heat and finger-protectant grills, keeping you safe while it’s powered on.

Buy it: Amazon

10. Mr. Heater 540 Degree Tank Top; $86

Mr. Heater/Amazon

Mr. Heater’s clever propane tank top automatically connects to its fuel source, saving you from having to bring any extra attachments with you on the road. With three heat settings that can get up to 45,000 BTU, the top can rotate 360 degrees to give you the perfect angle of heat you need to stay cozy. According to a reviewer, for a no-fuss outdoor heater, “This baby is super easy to light, comes fully assembled … and man, does it put out the heat.”

Buy it: Amazon

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Why Do Dogs Like to Bury Things?

Dogs like to dig.
Dogs like to dig.
Nickos/iStock via Getty Images

If you’ve ever found your dog’s favorite toy nestled between pillows or under a pile of loose dirt in the backyard, then you’ve probably come to understand that dogs like to bury things. Like many of their behaviors, digging is an instinct. But where does that impulse come from?

Cesar's Way explains that before dogs were domesticated and enjoyed bags of processed dog food set out in a bowl by their helpful human friends, they were responsible for feeding themselves. If they caught a meal, it was important to keep other dogs from running off with it. To help protect their food supply, it was necessary to bury it. Obscuring it under dirt helped keep other dogs off the scent.

This behavior persists even when a dog knows some kibble is on the menu. It may also manifest itself when a dog has more on its plate than it can enjoy at any one time. The ground is a good place to keep something for later.

But food isn’t the only reason a dog will start digging. If they’ve nabbed something of yours, like a television remote, they may be expressing a desire to play.

Some dog breeds are more prone to digging than others. Terriers, dachshunds, beagles, basset hounds, and miniature schnauzers go burrowing more often than others, though pretty much any dog will exhibit the behavior at times. While there’s nothing inherently harmful about it, you should always be sure a dog in your backyard isn’t being exposed to any lawn care products or other chemicals that could prove harmful. You should also probably keep your remote in a safe place, before the dog decides to relocate it for you.

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