Yes and no are two words that we use to reject, request, repair and enhance communication. In terms of children acquiring these words, research points out that expressing “no” happens before “yes” even in terms of physical development – in that your baby will most likely first learn shake her head side to side rather than up and down. This simple gesture still remains one the most universal gestures among infants and adults and develops later than other fine motor gestures such as pointing.
Infants also commonly use the gesture of “no” when they are offered something that doesn’t have interest in them, but this isn’t something they may naturally know how to do. We as communication partners shape this side to side movement for them and pair them verbal word “no”, so they overtime they use the head shaking appropriately to mean NO and we develop effective communication with our little ones to understand what they want.