When and Why a Baby Smiles

From The Parent Review

A baby's first smile is unforgettable. Just a few weeks after birth, that quick, small curve of the lips signals the beginning of a developmental journey that transforms an innate, spontaneous offering into a complex social expression of joy and invitation. A smile is more than charming; it is essential to a child's social and emotional future.

Before 1 month of age, an infant's smiles are predominately an inborn behavior, rather than responses to something he sees, hears or feels. These early smiles, reflexive and unrelated to social interaction, occur most often during deep sleep and the transitions between waking and sleep.

By 2 months of age, however, most babies begin to offer smiles in response to a pleasing or gently surprising external event: the appearance of their mother's face, a favorite toy or a sibling's grin. A combination of visual and auditory stimulation, or sights and sounds, is especially likely to elicit these delighted - and delightful - smiles.

The shift from spontaneous, internally motivated smiles to responsive, externally motivated smiles is due in part to an infant's growing ability to maintain eye contact and visual attention for longer periods of time. As a baby becomes more aware of his world, the frequency of these smiles increases.

Even the responsive smiles of a 2-month-old, however, are still strictly a reflection of the infant's internal response to something engaging. The next phase of smiling, social smiling, launches a baby's ability to share positive emotions with other people. Finally, he is able to communicate his personal feelings to the world at large.

The First Discovery:

When I smile, you smile!

The earliest social smiling occurs between a baby and a parent. Babies love faces; right from birth they will focus intently on their mothers' faces, and even on abstract images arranged like facial features. This kind of brow-knitting concentration is hard work for an infant, so she has two strategies to relax herself: She may look away, giving herself a break from the intense sensory input. Or, she may relax her brow and smile, which also releases tension.