Smiling back at you
Babies start smiling back at the people who care for them in their first weeks. In a four-country study, parents reported half doing so within the first month. Filmed studies found many more babies smiling at their mother at 3 months than at 6 weeks.
How sure are we?
Not sure yet. Only one study has measured the age so far, from parents' reports; filmed studies are small. How we know this
What it’s a sign of
Your baby is starting to share happy moments with you.
In filmed play, about 7 in 10 German babies smiled at their mother at 12 weeks, but only about 1 in 4 Nso babies in Cameroon, so how much babies smile may depend on how families play with them. Parents may also count very early smiles that researchers would not.
We don't yet know the age by which nearly all babies smile back.
A main source for the ages
Similarities and differences in child development from birth to age 3 years by sex and across four countries: a cross-sectional, observational study
Ilgi Ozturk Ertem, Vibha Krishnamurthy, Mphelekedzeni C. Mulaudzi, Yanina Sguassero, Hakan Balta, Ozlem Gulumser · 2018 · Lancet Global Health
- Children
- About 4,900 healthy children
- Where
- Argentina, India, South Africa and Turkey
- Ages
- Birth to 3½ years
- How
- Trained staff asked parents open questions about what their child could do, at health clinics
- What it found
- Found the age by which half of children reached more than 100 milestones. Most came at similar ages in all four countries, and for boys and girls. For example, half of children waved bye-bye by about 11 months and said a first word by about 9 months.
- Limits
- Only four countries and no rural areas, children from city clinics, and only healthy children (about half of those who came were left out for health reasons). It gives the age for half of children, not the full spread.
A main source for the ages
A cross-cultural comparison of the development of the social smile
Viktoriya Wörmann, Manfred Holodynski, Joscha Kärtner, Heidi Keller · 2012 · Infant Behavior and Development
- Children
- About 45 babies
- Where
- Münster in Germany, and Nso families in Cameroon
- Ages
- 6 and 12 weeks
- How
- Researchers filmed babies playing with their mothers
- What it found
- At 6 weeks, few babies in either place smiled at their mother during the filmed play. By 12 weeks, 7 in 10 German babies did, against 1 in 4 Nso babies.
- Limits
- Small groups, filmed for a short time; it measured how many babies smiled during the session, not when they first smiled.
If you’re worried about your child, talk to your child and family health nurse or GP.
Last checked 2 November 2026