There’s nothing better than the sound of your baby’s giggles. Laughter is an early form of communication, a moment of connection and social bonding that brings you and your baby closer. Once you hear that first irresistible laugh, you’ll want to hear it again and again. Learn how to encourage giggles, when to expect the first big belly laugh, and how your child’s sense of humor develops.

In this article:

• When do babies start laughing and giggling? 
• When do babies become ticklish? 
• How can I encourage my baby to laugh? 
• Why is my baby laughing in their sleep?
• Why is my baby not laughing?
• How does my child’s sense of humor develop?

When do babies start laughing and giggling? 

Your baby will likely giggle for the first time somewhere between 3 and 4 months of age. Laughing happens when babies combine a vocalization with a social smile. Your baby’s first laugh may be short and quiet. But over time, it will develop into full belly laughter ❤️

At first, it won’t be something funny that causes your baby to laugh—they don’t experience humor the way adults do. Instead, they’ll giggle because of something new or unexpected, or in reaction to you. 

When do babies become ticklish?

By around 6 months of age, your baby will respond to tickles with giggles and laughter.

As young as 4 months, their sense of touch is sensitive enough to identify when someone touches their foot or their belly, but they may not react as though they’re being tickled. Why doesn’t a 4-month-old show signs of being ticklish, even though they’re aware of a light, tickling touch? It may be because young babies have a limited visual understanding of their own bodies. They can feel their body being touched but may not be able to link that sensation to who or what is touching them. 

Being tickled isn’t just a sensory experience—it’s a form of social interaction, too. Your baby needs enough social awareness to understand the nonverbal cues that come with tickling, such as smiling, laughing, anticipation, and eye contact. They also have to learn how to connect the physical sensation with the person doing the tickling. So while your 4-month-old can feel your foot stroke or belly rub, they simply haven’t pieced together all the sensory components to giggle at a tickle…yet.

How can I encourage my baby to laugh?

To encourage that first giggle, try playing peekaboo. When your baby is very young, they don’t understand that you’re still there when they can’t see you. So when you hide your face and reveal it again, they’re delighted by the surprise. Making funny faces while looking in a mirror together might also make them laugh. 

When it comes to getting laughs from your baby, physical touch is especially effective. Try rubbing noses or kissing their belly, back, or neck. Funny sounds, like laughing, blowing raspberries, fake sneezes, and silly songs can also be a winning combination. Babies may also giggle at anticipation games, like “walking” your fingers up their belly while you gaze into their eyes. Follow this with a playful surprise, like a funny sound or face—pause to wait for their response. 

The key to getting laughs is to make eye contact and connect with your baby in fun, gentle ways. Always gauge their reaction while you play. If they become fussy, look away, or start to hiccup, it’s time to take a break. With a little experimentation, you’ll discover what your baby likes.

Why is my baby laughing in their sleep?

If you’ve seen your baby laughing in their sleep, you can probably tell it’s not a social laugh but more of an involuntary action. Researchers aren’t completely certain why babies sometimes laugh in their sleep, but it may be related to their sleep cycle. 

Like adults, newborns and older babies experience cycles of active sleep—also called Rapid Eye Movement or REM sleep—and quiet sleep, which is also called Non-Rapid Eye Movement or NREM sleep. But your baby can still move their muscles during REM sleep, while an adult can’t. Scientists suggest this may be why babies can laugh, smile, or twitch during their sleep.

Why is my baby not laughing?

Your baby may laugh easily, or not so easily, depending on their personal characteristics. Every baby has their own unique personality and temperament. 

If your baby is not yet laughing at 4 or 5 months of age, look for other signs of interaction. Do they vocalize and connect with you in other ways? Do they smile, initiate eye contact, and seem to enjoy playing with you? If so, there’s likely no cause for concern. Keep engaging in back-and-forth “conversations,” imitate your baby’s sounds and expressions, and enjoy lots of face-to-face time.

If your baby hasn’t laughed by 9 months of age, experts suggest talking with your pediatrician. 

How does my child’s sense of humor develop?

Laughing is an early sign of your baby’s developing communication and social skills. As they mature, you’ll begin to see more socially playful interactions—this is how you know they’re starting to develop their sense of humor 🙂 

By about 8 to 12 months of age, your baby may start their own game of peekaboo or even repeat something that made you or another person laugh. Your willingness to be silly and playful with them encourages their budding sense of humor. So when you find something that makes them laugh, do it again and again—babies love repetition.

Starting between 12 and 18 months, your toddler may begin to notice what is normal and what is unexpected or out of the ordinary, and find humor in contradictions. You can encourage their laughter by doing something silly. For example, pretend to drink from their bottle or cup, or try to balance a ball on your head and let it fall. 

As your child gets older, what they find funny changes along with their growing understanding of the world. Their sense of humor gives you a peek into the ideas they understand. For example, in toddlerhood, your child begins to know that many items have a certain place or use, and they often find “out of place” things funny. For example, they know that mittens go on your hands and socks on your feet. If you try to put a mitten on your foot or one of their shoes on their head, your toddler will probably find it hilarious. Later, as their language skills develop, your child will start to see the humor in wordplay or puns.

RELATED: Your toddler’s on top of the world when they make you laugh

Humor may support an important aspect of brain development because it engages both sides of the brain. The left side lights up when your child thinks of jokes, while the right side of their brain is activated by the social-emotional response to humor—laughing and appreciating the joke. 

Neuroscientists believe that hearing another person laugh triggers mirror neurons that make the listener feel like they’re laughing themselves. When you see a person laugh, mirror neurons fire that prompt you to imitate that action yourself. This is why laughter is contagious ❤️ These same mirror neurons are the ones that prompt you to show empathy toward someone. Laughing together with your child may help their brain “practice” this empathy.