According to Piaget, Egocentric Speech dies out and is replaced by Social Speech.
If you watch children play, for example, you will often hear them give a running discourse of what they are doing. An example is in the notes.
This discourse is the egocentric speech that Piaget was describing. They are speaking their movements. “Now I’m going in the house,” a child might say referring to a playhouse. “Now I’m feeding the baby.”
As the child becomes more adept at controlling their behavior verbally, the need to physically act out the speech act diminishes, as verbal imagery takes it’s place. Hence the quality of the egocentric speech likewise diminishes.
This was described by Piaget, you remember, as a dying out of egocentric speech as the thought processes mature.
NOTES: A repeat look at some egocentric speech examples.