Why does my newborn randomly smile?
Premature infants do more random, spontaneous smiling than full-term babies do. Smiling declines with age as it starts to come under voluntary control. At around six to eight weeks, infants start smiling in response to outside stimulus, first usually to sounds like a familiar voice and then to sights like human faces.
Why do babies smile in their sleep spiritually?
Since it’s impossible to really know whether babies dream, it’s believed that when babies laugh in their sleep, it’s often a reflex rather than a response to a dream they’re having. For example, many researchers note that babies may twitch or smile in their sleep during active sleep.