From the Guidelines
A child typically exhibits social smiling by around 2 months of age, with this milestone emerging between 6-8 weeks after birth. This important developmental milestone is characterized by the baby's ability to produce social smiles in response to external stimuli like a parent's face or voice, indicating that the infant is beginning to recognize familiar faces and respond to social interaction 1. Before this age, babies may smile reflexively during sleep or randomly, but these are not true social smiles. According to a study published in Pediatrics in 2015, group differences in social smiling were significant by age 12 months, but not at 6 months, in a cohort of high-risk infants later diagnosed with autism spectrum disorder (ASD) or typical development 1. However, it's essential to note that the emergence of social smiling can vary among babies, and some may start smiling socially a bit later. If a baby isn't smiling socially by 3 months of age, it may be worth discussing with a pediatrician as delayed social smiling can sometimes be an early indicator of developmental concerns, though many babies who smile late develop normally. Key points to consider include:
- Social smiling typically emerges between 6-8 weeks after birth
- Reflexive smiling during sleep or randomly is not the same as social smiling
- Delayed social smiling can be an early indicator of developmental concerns, but many babies who smile late develop normally
- The American Academy of Pediatrics recommends systematic surveillance during well-child visits to monitor developmental milestones, including social smiling 1.
From the Research
Social Smiling in Infants
- Social smiling is an important milestone in infants' socio-emotional development, emerging around 2 months of age 2
- Infants primarily smile in response to caregivers from 2 to 6 months, and after 6 months, they coordinate social smiles with other social cues to initiate interactions with the caregiver 2
- Studies have shown that full-term and preterm infants exhibit social smiles at 2-3 months of age, with no difference in the display of social smiles between the two groups 3
Age of Social Smiling
- Social smiling emerges around 2 months of age 2
- Infants at 3 months of age exhibit social smiles in response to happy/smiling and spontaneously interacting partners 3
- By 6 months, infants use anticipatory smiles to communicate pre-existing positive affect, which is linked to later social outcome 4
Factors Influencing Social Smiling
- The presence of a social recipient is important for infant smile production, with infants directing a majority of smiles to an attentive social object 5
- The use of protective facemasks by adults does not affect the display of social smiles in infants 3
- Social smiling is reduced in older infants with autism spectrum disorder (ASD), but may be typical in early infancy, with subtle differences in temporal coupling 2, 6