Why Do Babies Smile and Laugh in Their Sleep?

As new parents, there are many things to look forward to, one of those has to be seeing that first smile. Usually, the first genuine grin is a two-month milestone. But you actually don’t have to wait that long to see a little smirk or two.

Babies are able to smile even before being born. In the late stages of pregnancy, babies have shown to not only smile, but also laugh, blink and cry. They do this to prepare for life outside the womb.

Let’s take a closer look at the reasons why they smile:

Why Babies Smile in Their Sleep

When babies sleep, they go through different stages, just like we all do. One of the sleep stages baby will enter is REM, rapid eye movement, sleep. During this stage, the baby will sleep very lightly. This is also when the baby will dream the most, making his or her eyes move quite a lot.

The most precious effect of REM sleep is the little toothless grin the baby might make. Babies will often give their parents a huge smile while sleeping. While it’s sure to warm your heart—the baby is not exactly doing it for that reason.

The sleeping smiles in newborns are only reflexes. Experts say it’s similar to other actions a baby will do, such as sucking. It’s also believed that babies will smile in their sleep, as a survival instinct.

Older children and adults often smile, laugh, talk or even scream while in the REM stage. It’s all a result from the rapid dreaming we’re going through.

Adults will only stay in the REM stage very shortly. Young babies, on the other hand, will actually spend half of their sleeping time in this stage.

Smiles often happen very quickly and only last a few seconds. At times, it might look more like a grimace than a loving smile, but that doesn’t make it any less precious.

It’s not always noticeable; even if you’re an attentive parent, you can easily miss it. The sleepy smiles usually fade as the baby matures.

Babies often let out a very noticeable laugh. This can sometimes be a cute little giggle or even a chuckle.  

The baby might also flick its arms or legs, and even twitch a little. This is all normal. You might even notice the eyes opening, even though baby is still asleep. Some infants will also look cross-eyed during the REM stage. Again, this is nothing to worry about.

Stage 1, 2, 3 and 4

There are four stages of sleep, which the baby will go through before entering REM. Here’s what to expect:

  • Stage one: Your baby is becoming drowsy, eyes may open and close.
  • Stage two: Very light sleep, baby might be startled by noises or movements.
  • Stage three: Baby will enter into a deep sleep.
  • Stage four: Baby is sleeping very deeply.

The baby will go through stages one to four and then reverse, ending up in REM sleep. Baby might wake up when changing between stages, and some will even have a hard time going back to sleep.

Other Reasons for Sleepy Smiles

Smiles are usually a sign of happiness and contentment. However, in young babies, it can also be a sign of discomfort.

You might notice that the adorable gummy smile is often followed by a suspicious scent. That’s right, smiling baby could mean gassy baby. The baby often lets out a little grin before, during or after passing gas.

Sometimes a smile is followed by a little cry, this is also due to the REM stage. This often wakes up parents; but if you leave baby for a minute, they might calm down again.

First Real Smile

The first real smile, also called a social smile, can happen anytime from around six weeks. These are completely voluntary reactions to what the baby sees or hears.

First smiles are often a response to funny voices, music or other noises. Later, as the baby’s vision advances, they will begin reacting to facial expressions and actions.

Why Is Smiling so Important?

A smile is much more than just a way to express happiness, it’s also a crucial part of your baby’s development. As the baby begins to socially smile, it shows that his or her vision as well as hearing is working.

It also shows that their brain is developing and neuro skills are advancing. As babies grows, they will begin to learn how to identify and recognize the people around them. Social smiles last for much longer, and are responses, not reflex.

How to Help Your Baby Learn

Practice always makes perfect. Therefore, it is essential to help your baby develop and use their new-found skill. Some babies will smile and laugh at anything, while others need a little more humor.

Try these methods to make your bundle of joy smile:


Playing with an infant is not exactly an action-filled activity. Holding your baby close, looking into their eyes is sometimes all the fun they need. Try to play a fun game, such as peek-a-boo.

Blowing raspberries is also an infant favorite. There is just something irresistibly funny about mommy or daddy when they’re making fart noises.


Singing to your baby can help to bring out a little smile, maybe even a giggle. Don’t limit yourself to lullabies or kids songs. Any music will do, the most important part is that you enjoy it. If your baby can sense that you’re happy, so will they be.

Communication Is Everything

Always communicate with your baby using your voice and facial expressions. This will not only help them to smile, but it will also develop their social skills and language.

Smile whenever you are talking to your baby, and they will soon try to imitate that. Showing him or her how to move their face is essential part of their development.

You might notice how your baby is gazing deep in your eyes, this is one of their favorite activities. Try to keep eye contact for as long as possible, you might just get a little grin.

Final Thoughts

Seeing your baby smile for the first time is one of the pure pleasures of parenthood. Whether it’s in their sleep or because of gas, it’s still a lovable memory.

Remember, all babies develop differently. Some might show their first social smile at six weeks, while others are as old as three months.

Always communicate with your baby, and once you find that action they find funny, repeat the behavior to see what happens next. You won’t be disappointed!

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