Question
When do newborns typically start to smile? My child is already 42 days old but has not been able to be amused yet. Does this mean there is a problem with intellectual development? Can intelligence be tested? There is information suggesting that newborns can smile as early as 40 days old. Is this accurate?
Answer
Newborns are born with the ability to see, capable of brief primitive staring and following slowly moving objects within a close distance. They can adjust their vision within about 15 centimeters and have coordinated eyesight. The smiles of newborns are actually physiological responses; this type of smile is a signal of brainstem brainwave activity, not just an expression of happiness. Around 5 weeks after birth, the smiles of infants begin to correlate with their feelings, with laughter being an experience of physiological emotion. When infants feel internally comfortable, they express this through smiling. Therefore, at 42 days old, if a newborn has not yet been able to be amused…