When Do Babies Start Smiling?

The first time your baby smiles at you, they go from a treasured being whose survival is totally dependent on you (it's a lot of pressure) to a charismatic kid with a fascinating personality. It's a milestone parents everywhere eagerly await, and it marks an exciting step in your baby's development.

In this guide, we’re breaking down the different types of baby smiles (yep, there’s more than one) and sharing expert tips to help bring on those sweet little grins.

The importance of your baby's first smile

"As both a doctor and a mom, I know how powerful that first smile can be," explains Jodie Spangler, MD, a family medicine physician and mom of two. "It’s not just a milestone; it’s a tiny, gummy love letter that melts us and brings a sense of joy to those early, sometimes overwhelming weeks.”

But why does this particular milestone tug at our heartstrings so much? According to Spanger, it's because smiling is also one of the earliest ways babies communicate and connect with the people around them. "When a baby smiles and a caregiver smiles back," she notes, "it creates a feedback loop that strengthens bonding, builds trust, and even helps the baby’s brain develop crucial pathways for social interaction."

And perhaps most touching of all? That first real smile is a sign your baby is truly noticing you and starting to interact with the world. “A genuine social smile shows the brain is beginning to build connections for things like visual tracking, memory, emotional regulation, and social give-and-take,” Spangler adds. “It means your baby is starting to recognize faces, pick up on emotions, and respond with intention.”

What are the different kinds of baby smiles: reflex smiles and real (social) smiles  

You might think every baby smile is the same, but each one has its own special charm and developmental meaning.

Dr. Eileen A. Dolan, M.D., section lead of developmental and behavioural pediatrics at Joseph M. Sanzari Children's Hospital, explains that there are several types: reflexive, social, responsive and anticipatory smiles.

Beyond their cuteness, these smiles mark important milestones, showing how your baby is learning and connecting with the world. Let’s take a closer look at what each type of smile means for your little one.

Reflex smiles

Dolan explains that reflex smiles, sometimes referred to as reflexive smiles, are often the first type of smile parents notice on their newborns. Unlike social smiles, which are intentional and sparked by interactions with others, reflex smiles happen involuntarily. "These smiles are involuntary and driven by internal factors, while social smiles are intentional responses to external social stimuli," she says.

So, what’s going on behind these tiny, spontaneous smiles? According to Dolan, "Reflex smiles are thought to be related to spontaneous activity in the lower brain regions. They're likely connected to the development of neural pathways and the release of endorphins. They're not a conscious expression of emotion."

It’s interesting to note that reflex smiles can appear as early as birth, and sometimes even before. "They are commonly seen in the first few weeks of life," Dolan points out. "These smiles are usually brief, often lasting just a few seconds. You may notice reflex smiles during REM sleep, when your baby feels sensations like a full tummy or passing gas, or even in response to a gentle touch."

Social smiles

Unlike reflex smiles, which Dolan explains are usually just a simple upturning of the mouth’s corners, social smiles are a whole-face affair — think eyes that crinkle or twinkle, not just lips that curl. These more expressive smiles usually pop up in response to something familiar, like a parent’s face or voice. As Dolan adds, “They are also spontaneous and related to internal states.”

Given how much parents crave those first signs of connection, it’s easy to see why they might confuse reflex smiles with social ones during the early weeks. "This is completely normal," Dolan reassures. "After all, reflex smiles can look almost identical to social smiles at first, especially when you’re just getting to know your baby.  The subtle differences in eye involvement and the context of the smile (e.g., during sleep versus while interacting) can be hard to distinguish at first."

While reflex smiles might not be the social milestone parents are waiting for, Dolan emphasizes that they still play an important role. "Those early smiles, even reflex smiles, are a beautiful part of the experience of sharing your life with a newborn," she says.

Responsive smiles

According to Dolan, responsive smiles are the next step after social smiles. They're a way for babies to show they are enjoying something, like hearing a playful sound or spotting a favorite toy. "You'll often start to notice these smiles when your baby is around two to three months old," she says.

Anticipatory smiles

Finally, there are anticipatory smiles, which Dolan describes as the most complex type of early smile.

"These smiles often show up just before something enjoyable happens, hinting that a baby is starting to recognize when good things are about to unfold," she explains. "You might notice this smile when your baby expects to be tickled or when they see a parent return after stepping out for a moment."

Anticipatory smiles usually begin to appear between 9 and 12 months of age. "Their emergence offers a glimpse into a baby’s growing understanding of cause and effect, marking an exciting step forward in cognitive development," adds Dolan.

When to expect your baby's first social smile

If you’re wondering when your little one might share their first social smile, Dr. Marquita Lyons-Smith, a Doctor of Nursing Practice (DNP) and Certified Pediatric Nurse Practitioner (CPNP-PC), explains that most infants start to show their first social smile between six and eight weeks of age.

Some infants, however, might smile a bit earlier or later, and that’s completely normal. “In my 20 years of practice, I most commonly observe full-term infants begin to socially smile within the five to seven week timeframe,” she shares.

However, if a baby's smile is significantly delayed, Lyons-Smith suggests that providers may begin monitoring for other developmental concerns and advise parents according to each unique situation.

What makes babies smile?

“The most common triggers for social smiles in babies are close, face-to-face moments with parents, caregivers, or siblings—think: smiling faces, happy expressions, and gentle touches,” explains Dr. Madhushree Desiraju, MD, a primary care physician with Nemours Children’s Health.

So, why are these interactions so powerful? It turns out that babies are biologically primed to recognize and mirror familiar faces, making these exchanges essential for their growth. "Positive attention and engagement encourage mirroring and synchrony, which are reinforced by repetition,” Desiraju says. "Over time, these moments help babies learn to initiate playful behaviour as they reach new milestones."

But it’s not just about what babies see. What they hear matters, too. For example, familiar voices using playful ‘baby talk’ can light up a baby’s face. According to Desiraju, "Baby talk from a familiar caregiver has been shown in studies to be especially attractive to babies and serves as a very effective social cue for drawing the infant’s attention, creating a foundation for early social communication and bonding with caregivers."

Touch also plays a starring role; gentle cuddles or a game of peek-a-boo can spark smiles as babies grow, Desiraju notes. “Gentle touch increases parasympathetic activity, leading to calm states,” she adds. "Cuddling stimulates a baby’s reward and stress-regulation systems, fostering positive emotions and social connection. Predictable games like peek-a-boo also help babies engage and bond with caregivers.”

How to encourage your baby to smile

Looking for ways to invite more smiles from your little one? These simple suggestions could help:

Spend face-to-face time with your baby

Spending face-to-face time and maintaining eye contact can help elicit those first smiles from your baby.

According to Jen Jones, an early childhood educator of more than 30 years, “Eye contact can make babies feel safe and connected. It creates the foundation for social bonding and gets them started on recognizing familiar faces. When combined with a smile, eye contact enhances emotional connection and leads babies to react in kind.”

Talk, sing, and make silly faces at your baby

Babies thrive on expressive communication, so Jones recommends talking, singing, and making silly faces to encourage them to smile.

“Your intonation, tempo, and facial expressions during songs or lighthearted moments provide joyous, engaging stimulation,” she says. “These interactions not only elicit smiles, but also encourage early language development.”

Respond enthusiastically

When your baby makes sounds or expressions, Jones suggests responding with enthusiasm.

She explains, “Responsive interactions show your little one that their attempts to communicate are valued. This builds trust, fosters emotional connection, and encourages them to engage more deeply.”

Offer plenty of cuddles and gentle physical affection

Physical closeness matters, too. “There is security in physical proximity,” says Jones. “And when you’re cuddling, rocking, or holding a tranquil baby, you’re likely to feel happy and relaxed."

Smile at your baby often

Also, remember that babies are natural imitators; smiling at your baby teaches them how to smile back.

“Babies are wired to imitate,” Jones shares. “If you smile, your baby learns to link smiling with joy, safety, and attention. As they get older, they start smiling back for social reasons as part of their emotional development.”

Smiling is a key developmental milestone

Dr. Marilyn Griffin, senior clinical solutions medical director of behavioural health at Aetna Better Health of Illinois, explains that your baby’s first smile is more than just a sweet moment; it’s a meaningful developmental milestone that gently weaves into their social and emotional growth.

As she puts it, “Smiling is one of the earliest and most important ways babies begin to connect with their caregivers and the world around them.” In other words, this early smile is a small but important step toward intentional social interaction, helping to lay the foundation for emotional expression, bonding, and healthy attachment.

Of course, the journey doesn’t stop with that first smile. Griffin notes that “Cooing, laughing, and babbling usually follow a baby’s first smile. These milestones are often built upon each other over two to nine months.” In other words, each new skill tends to support the next, creating a gentle progression in your baby’s development that can be wonderful to witness.

Looking ahead, Griffin shares that first giggles and laughs often appear around three to four months of age, especially during playful moments or when babies hear familiar voices. She adds, “These first laughs are an exciting sign that they are enjoying social play and developing more ways to express delight.”

What if your baby isn't smiling yet?

If your baby hasn’t started smiling yet, it’s completely understandable to feel a bit anxious. Still, as Stephanie Jeret, CCC-SLP, a licensed speech-language pathologist, points out, it’s important to remember that every baby develops at their own unique pace.

"Factors such as prematurity, sleepiness, hunger, or underlying medical issues can all influence when a baby reaches this milestone," Jeret says. "So, if your baby isn’t smiling just yet, it’s not necessarily a cause for alarm."

On top of that, your baby’s temperament can play a big role in how and when they smile. "Some people naturally smile more than others, and the same is true for infants," adds Jeret. "While some babies may be more expressive and easygoing, others may be more observant or reserved. Smiling less frequently doesn’t necessarily indicate a problem—it may simply reflect a baby’s individual temperament."

That said, if your baby hasn’t started social smiling by around two months, it’s worth bringing up with your pediatrician at your next visit. "Your pediatrician can help determine whether your baby is meeting developmental milestones or if further observation is needed," Jeret explains. "They'll also consider other behaviours, such as making eye contact, responding to sounds, and engaging with their surroundings. While these signs aren’t always cause for concern, they do give your pediatrician helpful clues to make sure your baby’s development is on track."

The joy and importance of your baby's smile

There’s something quietly special about your baby’s very first smile. Beyond how sweet it looks, Dr. Yelena Gidenko, PhD, a licensed clinical mental health counsellor supervisor and certified brain health professional with over twenty years of experience in neurodevelopment and early relational health, shares that this early smile carries a deeper meaning.

“It’s your baby’s gentle way of beginning to connect with the world, and especially with you,” Gidenko explains. “For parents, seeing that first real smile can be truly touching. It’s a quiet reminder that the bond between you and your little one is growing, little by little.”

Although babies can’t express their feelings with words just yet, Gidenko notes that this first smile often feels to parents like a gentle ‘I know you’ or ‘this feels nice.’ She continues, “Put simply, it’s an early form of social communication—an unspoken message that says, ‘I recognize you, and I love being with you.’"

Experts

• Dr. Yelena Gidenko, PhD, is a licensed clinical mental health counsellor supervisor and certified brain health professional.
• Stephanie Jeret, CCC-SLP, is a licensed speech-language pathologist.
• Dr. Marilyn Griffin is the Senior Clinical Solutions Medical Director of Behavioral Health at Aetna Better Health of Illinois.
• Jen Jones is an early childhood educator with more than 30 years of experience.
• Dr. Madhushree Desiraju, MD, is a primary care physician with Nemours Children’s Health.
• Dr. Marquita Lyons-Smith, DNP, CPNP-PC, is a certified pediatric nurse practitioner.
• Dr. Eileen A. Dolan, MD, is the Section Lead of Developmental and Behavioral Pediatrics at Joseph M. Sanzari Children's Hospital.
• Jodie Spangler, MD, is a family medicine physician and mom of two.