A baby's first social smile usually appears by the end of their second month. That's one reason why, as a pediatrician, seeing babies and their parents at the 2-month-old checkup is always a great pleasure.
The exhausting days when they were newly home from the hospital are behind them. The baby's fussy,
crying-for-no-good-reason periods are becoming less frequent. The parents and baby have finally started to develop a rhythm to their days and nights. Now awake for longer periods, babies start to communicate in the best way they know how–through their smiles.
At this milestone checkup, I will ask parents, "Is she smiling yet?" and they often can't resist some show-and-tell. They may smile at the baby and gently croon or tickle her. The baby then obliges by smiling back with a happy wiggle. They may even coo, another social skill babies usually start working on this month. Sometimes I wonder how parents get anything done around the house with all this delightful back-and-forth going on.
"Oh, she's been smiling like that since Day 1."
Often, parents will remark that they've seen the baby smile at them practically since birth. I'm never going to disagree with a proud parent on that point. However, it's probably not exactly true. Yes, there are some adorable grimaces and grins that parents notice in baby's first month. Where do these come from? We don't quite know. It often seems like the baby is responding to some internal signal, like gas or hunger.
Those primitive, often random grins are indeed different from the social smile that we'll see weeks later. Whenever the parents of a 2-week-old infant say that their baby is already smiling, I simply tell them, "Just wait, it gets even better."
Why is the social smile different?
Babies spend more of their second month awake and paying attention to all they see and hear around them. They learn that their family cares for them when they are hungry or fussy or tired. They likely feel excited and loved when people smile at them, and one day their own smile breaks out in return. Then, the captivating "smile talk" begins.
I often borrow a tactic from pediatrician and author T. Berry Brazelton, who wrote about watching babies try to catch their parent's attention during office visits. The parent may be cradling the baby while talking to me. Meanwhile, the baby watches the parent's face intently, as if waiting for their chance to engage.The baby may vocalize or wriggle around in their parent's arms.
Then, when the parent pauses our adult conversation to look down, the baby will break out into a proud, wide smile. Her smile caught her parent's attention, and she got a warm smile back in return. In this way, the baby starts to feel good that she knows how to control her own little world in other ways besides crying and fussing.
What if it seems like my baby is smiling past me, like at the lamp or the curtain?
Some babies may not be ready at first to watch a parent's face for a long time. It may be just too overwhelming for them to look directly into their parent's eyes. By looking just past a parent's face, a baby still is learning about the parent's touch, gentle voice, and facial expressions. With more practice, they will be able to hold their gaze for longer periods.
What's so important about all this back-and-forth smiling?
In addition to all the warm fuzzies the social smile brings, it is also an important part of a baby's
social and emotional development. When you reliably respond to your baby's cues about when they are ready for play and when they need a break, you let them know that their thoughts and feelings are important.
Because a baby's smile gets such a predictable response from a parent, they start to feel confident that they can exert some control over their world. The child's self-esteem starts to grow, even at this young age.