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Anna Davies
Contributing Writer

When Do Babies Smile?

It’s the moment you can’t wait to see (and share!)—when baby finally breaks out in a gummy little grin. Find out when you can expect baby to start smiling.

When do babies smile? Turns out, baby has been perfecting that picture-perfect smile long before arriving on the scene: Reflex smiles actually happen in utero, between 25 and 27 weeks gestational age. But this type of baby smile is not in response to an emotional trigger—it’s just a biological way for baby to start practicing different skills. And baby’s not just smiling. Along with sucking, blinking and even crying, baby can be captured via ultrasound “testing” his smiling abilities long before birth.

But do newborns smile? It’s certainly possible! After baby arrives, it’s not uncommon for some parents to see a reflex smile from day one, says Debra Goldenring, MD, pediatrician at Summit Medical Group in Livingston, New Jersey. “Contrary to the name, reflex smiles aren’t in response to anything,” Goldenring says. “They occur randomly and can even occur during sleep.” In fact, sleep is the most common time to see your smiling baby!

Why do babies smile when they sleep? Similar to how we sometimes make expressions or talk in our sleep, babies make lots of funny faces while sleeping, including smiling. According to justthefactsbaby.com, these “smiles are spontaneous and often occur when baby is drowsy or during REM stages of sleep.” Being gassy while sleeping can also trigger this smile reflex.

Regardless of whether baby is asleep or awake, reflex smiles tend to only last a few seconds and can look like a grimace. In fact, the smile you see will probably be super short, probably lopsided and often happen when baby isn’t looking at anything in particular. Not all babies exhibit reflex smiles, though, and because they’re so blink-and-you’ll-miss-them, they can be hard to spot for even the most attentive caregivers. So now that you know about reflex smiles, you’re probably anxious to find out when do babies start smiling for real (aka a baby social smile)?

When Do Babies Smile On Purpose?

You’ve probably heard that 6 weeks old is the most common answer to when do babies start smiling, but these are reflex smiles, and by 2 months those will disappear. That said, every baby develops at her own pace, and it’s not unusual for baby to take until the three-month mark to smile on purpose, Goldenring says. How can you spot the difference between a reflex smile and a baby social smile during those first few weeks? See if you can drag your eyes away from her adorable upturned mouth for a moment and look into her eyes, Goldenring suggests. When baby is giving a social smile, she’s also engaging in eye contact. A baby social smile also happens when baby is awake, and will likely look less lopsided and more symmetrical than a reflex smile. “It’s also longer; she wants to connect and will hold it until she gets feedback in the form of a smile or eye contact from you,” Goldenring says.

Baby’s first smile is a key milestone in infant development: It’s important for baby because it signals that her vision and nervous system have not only matured enough to be able to zero in on your face and eyes, but that she recognizes a smile is a way of communicating with the world around her. By 6 months, smiling baby will be more selective with whom she shares a smile; baby will share them with the special people in her life, but around this time, new faces may cause crying. That’s completely normal and a sign that baby is beginning to separate the world into the people she knows and strangers.

When Do Babies Smile At Parents?

A baby’s first smile is a major milestone for parents too. And it’s a gift that keeps on giving: The more encouragement you give, the more he’ll want to practice his newfound expression. Smile back, clap and talk to him when he gives you a grin. The more you interact, the more you’ll be able to see unique differences in the types of smiles he gives, whether it’s a “good morning!” smile or a “oh, wow, this toy feels good in my mouth” smile. And even though babies tend to reserve their very first smile for the people they know best (like you!), don’t worry if Grandma gets the first baby smile —or even the stranger at the supermarket. It’s not a sign that baby likes them better; it’s just his way of saying, “Hey, I see you. You’re interesting.” He’ll soon share his smile with you too, so do not fret.

How To Make Your Baby Smile

“Just like adults, some babies are more serious than others and may be more selective with their smiles. Again, this says nothing about whether or not they love you—they do!—it’s just a sign how they’re naturally wired,” Goldenring says. If you’re wondering how to make your baby smile on purpose, certain games and activities can help. For starters, Goldenring suggests giving baby your widest grin whenever possible. “Babies are very good mimics. If they see you smile a lot, chances are they’ll try to emulate the expression,” she says. Then try some or all of these other smile-inducing tactics:

  • Get close and be dramatic. Newborns are nearsighted (their full visual capacity doesn’t happen until about 3 months), so make sure baby has plenty of opportunities to be up close and face-to-face with you—about a foot away is ideal. Talk or sing to baby and exaggerate your expressions: Let your eyes get wide, your smile get broad and really show baby what a happy face looks like.
  • Play games. Games like peekaboo are also great to engage baby. The element of surprise at being confronted with your familiar face can excite baby enough to elicit a baby smile. In fact, babies often respond to surprise with a smile, so engage baby with toys that make different noises or squeaks, stuffed animals with various textures or read a book and change your voice for the different characters.
  • Get physical. If you’re wondering how to make your baby smile, engage with her physically. Tickle her belly or give her raspberry kisses as you change her diaper. Sit on an exercise ball and gently bounce up and down or lie on your back on the floor and lift her up into the air, bringing her down to kiss her. “The more you engage with baby, the more she’ll want to engage with you,” Goldenring says. As baby learns that a smile elicits an even bigger grin from you, baby will up the ante by adding laughter, coos and other cues that she’s your No. 1 fan.

What If Baby Doesn't Smile?

“It’s a question I get asked all the time in my practice, and it’s one I tell new parents not to worry too much about, especially in the first few months,” Goldenring says. “Your baby will likely be smiling at 3 months. But if baby doesn’t smile often, that doesn’t mean anything is wrong with him. Just like adults, babies have different temperaments.”

If baby doesn’t smile yet and you are concerned when do babies smile, remember that it’s far more important to observe baby’s level of engagement with the world. Regardless of baby’s smile status, by 3 months old, baby should be “communicating” with you, other caregivers and even strangers via eye contact and vocal expressions (for example, making protesting noises when baby’s pulled away from the bottle or breast). If baby’s not doing any of that by 3 months, bring up your concerns with your pediatrician. “Often, a parent’s concern is that if their baby doesn’t smile, that means he or she is autistic. But autism isn’t something that is diagnosed in infancy,” Goldenring says. (Autism and other spectrum disorders generally aren’t diagnosed until 18 months to 2 years old.) Some autistic babies smile; some don’t. “But not smiling or engaging is something we want to check out,” says Goldenring, adding that occasionally, a young baby doesn’t smile because they may have a vision problem that needs addressing.

Bottom line: When it comes to how to make your baby smile, you don’t need to have Tina Fey– or Amy Poehler–level comedy skills. Baby will do it when she’s ready. The more grins you share with baby, the more you’ll be rewarded with smiles. So have your smartphone camera ready to share #babysfirstsmile with the world any day now.

The Bump and the Maker of Orajel present Little Smiles, your guide to caring for baby’s teeth and gums for a happy, healthy smile. Visit Orajel.com for more on children’s dental care.

PHOTO: Yuko Hirao