Around 2 months of age, your baby will have a "social" smile. That is a smile made with purpose as a way to engage others. Around this same time to about 4 months of age, babies develop an attachment to their caregivers.

What is the earliest a baby can smile?

Sometimes a smile in the early weeks of life is simply a sign that your little bundle is passing gas. But starting between 6 and 8 weeks of life, babies develop a "social smile" -- an intentional gesture of warmth meant just for you. This is an important milestone.

Can babies smile at 4 weeks old?

It may be possible for your baby to smile at 4 weeks but usually only while he's sleeping. This is called a reflex smile. Your little one may not flash a true smile until about 6 weeks or a little older, and these true smiles happen when he's awake and alert.