Month two is when something shifts. Up until now, you've been doing everything for someone who can't acknowledge you. That changes this month. The social smile arrives — your baby smiles back at your face specifically — and it reorganizes the entire relationship.
I remember the first time Second Son smiled at me. Not the gassy, random newborn twitch. The real one — looking straight at me, a beat of recognition, then the smile. It's the milestone that makes the first month feel like it was worth it. And it is. But it also carries clinical weight that most parents don't know about until later.
The Social Smile: The Most Important Milestone of Month Two
A social smile is a smile triggered specifically by a face and a voice. Not by gas. Not by a dream. By you.
It typically first appears around 6 weeks and should be consistent by 2 months. Here's how you tell it from a reflex smile: the social smile has a clear trigger (your face and voice), a brief delay (your baby processes what they're seeing before they respond), and eye contact. A reflex smile shows up randomly — during sleep, while gassy, without any social trigger. No eye contact. Comes and goes.
With First Son, I thought all his early smiles were the real thing. I was describing them to people at four weeks as if he was already charming. Looking back, most of them were reflex. The genuine social smile came later, and I hadn't been tracking when.
With Second Son, I knew the difference. I knew what I was looking for and when I expected to see it. When the real one showed up at 6.5 weeks — eye contact, delay, triggered by voice — I wrote it down.
That matters for more than memory. The social smile is also the earliest behavioral indicator screened for autism spectrum disorder.
⚠️ No social smile by 3 months
It's one of the earliest and most reliable clinical flags for autism spectrum disorder. Don't wait for the next scheduled visit. Call before.
And beyond the clinical side: every time you smile and they smile back, every time they coo and you respond — those exchanges are building neural pathways for language and attachment. The research calls it serve-and-return. It starts here.
Motor Milestones: Month Two
- Head lifting to 45° during tummy time — More consistent than last month, still not steady. Support the head whenever you're holding them upright.
- Visual tracking — Hold a face or bright object 8–12 inches away and move it slowly. They should follow it. This is new.
- Hands starting to open — The tight newborn fist begins to relax. Swiping begins. They'll briefly hold things placed in their palm.
- Consistent startle reflex — Still responding to sudden loud sounds. This will fade over the next few months — that's normal.
Tummy Time: You Should Have Started Already
If you did, good. Keep building.
If you haven't — it's not too late before 3 months. Start with 30-second bursts, build up, use the chest position if the floor is resisted. The goal is 20 minutes per day by 4 months, spread across the day.
The window to prevent positional flat head closes around 6 months. The muscle foundation for rolling, sitting, crawling, and standing is being laid right now. This is not a nice-to-have.
I've already covered this in the 1-month article. The message doesn't change at 2 months: do it now, do it consistently, discomfort is not harm.
Language: Cooing Starts Here
Cooing — soft vowel sounds, "ooh" and "ahh" — begins around 6–8 weeks and should be consistent by 2 months. It's your baby's first intentional vocal communication.
The right response is conversation. Coo back. Pause. Let them respond. This turn-taking structure is the earliest form of the back-and-forth that all language is built on. You're not just entertaining them. You're building the neural architecture for language, one exchange at a time.
With First Son, I talked at him a lot. Narrated what I was doing, explained things. That's useful. But I didn't pause and wait for him to respond. I didn't understand the importance of the back-and-forth specifically. With Second Son, I treated every coo like a question that deserved an answer and a wait.
No cooing by 2 months is a clinical red flag worth raising immediately — it may point to hearing concerns or a developmental delay. Don't wait for a scheduled visit.
The 2-Month Well-Child Visit
This is the first major vaccine appointment. Know what's coming so you're not caught off guard.
Your pediatrician will check: social smile, cooing, head control, and visual tracking. Those are the four developmental markers for this visit.
Vaccines at 2 months
| Vaccine | What it covers |
|---|---|
| Hib | Haemophilus influenzae — meningitis protection |
| PCV15 | Pneumococcal — pneumonia, meningitis |
| Rotavirus | Oral vaccine — severe diarrhea and vomiting |
| IPV | Polio |
| Hep B | Hepatitis B — dose 2 of 3 |
Your baby will likely be fussy and may run a low fever for 24–48 hours. That's a normal immune response. Ask your pediatrician for infant acetaminophen dosing based on your baby's current weight — get the number before you leave the office.
With First Son, we left that appointment without asking about dosing and spent two hours that evening trying to find the right answer online. With Second Son, I asked before we walked out.
Three questions worth asking at this visit
- Is the social smile where it should be — and what's the flag timeline if it isn't?
- How much tummy time should we be doing now, and what if they still resist it?
- Should we start vitamin D drops? The AAP recommends 400 IU/day for breastfed babies starting shortly after birth — this visit is the right moment to confirm it's in place.
On the swaddle: rolling signs typically appear between 2–4 months. Once rolling starts, the swaddle has to go. Your pediatrician can tell you what to watch for.
What to Do Right Now
- Test for the social smile. Get face-to-face, 8–12 inches, and talk to them. Look for eye contact, a beat of processing, then the response. If you're not seeing it consistently by the end of month two, bring it up before the 3-month mark.
- Start a tummy time routine if you haven't. Build toward 20 minutes a day. Use the chest. Build up slowly.
- Have a conversation with your baby. Coo back, pause, wait. Let them respond. Do it every day.
Month two is when this stops being one-directional. That social smile is the first signal that they know you — specifically you. Everything that follows is built on that foundation.
Scout tracks what's opening month by month
Every month, on your child's monthly birthday, Scout sends an email timed to their exact developmental age — what windows are open, what's closing, and exactly what to do. Plus a calendar invite so nothing slips.
Try Scout Free →Frequently Asked Questions
What milestones should a 2-month-old be hitting?
The social smile is the headline — a genuine smile triggered by a face and voice, with eye contact and a brief delay. Beyond that: cooing, visual tracking, head lifting to about 45° during tummy time, and a consistent startle reflex to sudden sounds. The 2-month well-child visit checks all of these.
With First Son I couldn't have named those off the top of my head. With Second Son, I walked in knowing exactly what the pediatrician was going to look for.
What is the social smile and when does it appear?
It's a smile triggered specifically by a face and a voice — not gas, not a reflex, not a ceiling fan. First appears around 6 weeks, should be consistent by 2 months. The tell: eye contact, a brief processing pause, then the response. Absent social smiling by 3 months is one of the earliest clinical flags for autism spectrum disorder. Don't file it away for the next scheduled visit — call.
What vaccines does a baby get at 2 months?
DTaP, Hib, PCV15, rotavirus (oral), polio, and hepatitis B (dose 2). Six vaccines at one appointment. Your baby will likely be fussy and may have a low fever for 24–48 hours — this is normal. Before you leave the office, ask your pediatrician for infant acetaminophen dosing based on your baby's weight. You'll want that number before you need it.
When should I start tummy time?
Month one, ideally day three. If you're reading this at 2 months and haven't started consistently — start now. Build in 30-second increments, use a parent's reclined chest if the floor is resisted. The goal is 20 minutes per day spread throughout the day by 4 months. The window to prevent positional flat head closes around 6 months.
When do babies start cooing?
Around 6–8 weeks, consistent by 2 months. The right move when they coo: coo back, then pause and wait. That back-and-forth turn-taking is the earliest scaffolding for language. No cooing by 2 months is a clinical red flag — raise it immediately, don't file it away for the next visit.
Next month: rolling attempts begin, the hands really wake up, and the swaddle transition becomes urgent.