At what age does a term infant first show a social smile, that is, smiling in response to the mother's face or voice rather than an internal or reflexive smile?
- A At birth
- B 4 months
- C 6 to 8 weeks ✓
- D 6 months
Correct answer: C. 6 to 8 weeks
Explanation
The social smile appears at 6 to 8 weeks (about 2 months) and is one of the earliest social milestones. The smile at birth is endogenous or reflexive and occurs during sleep, while smiling at a mirror image comes later around 5 months. A child who shows no social smile by 3 months warrants developmental evaluation, making this a key screening landmark at the 6 to 8 week visit.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.