Symbolic behavior is exhibited in the Sensory--Motor Stage.
Symbolic behavior may first take the primitive form of creating an affinity for some useless object like an old worn-out blanket. Primates, who have a toe-hold on language, also do this with things like rocks and mushrooms etc.
A little later, the imitation of movements and sounds by the infant carries some symbolic significance.
Imitation leads to pretending,, and than objects become props (symbols) in the baby’s mind.
The big guns for parents in facilitating symbolic development is reading! At first, of course, when they are just a week old, reading serves other linguistic purposes, which we will describe later.
But as language dawns upon the child’s awareness the reading process becomes a powerful catalyst to the development of the symbols.
The Pre-Operational Stage (2 - 7 years):