'Collective Monologue leads to egocentric speech'. Which psychologist viewed this strongly ?

 Jean Piaget:

• Jean Piaget was a Swiss developmental psychologist who is best known for his theory of cognitive development. He believed children's cognitive development progresses through four stages: sensorimotor, preoperational, concrete operational, and formal operational.
• Children are egocentric in the preoperational stage, which typically occurs between the ages of 2 and 7. This means that they are unable to see things from another person's perspective. As a result, they often talk to themselves or others without really communicating. This type of speech is called collective monologue.
• Piaget believed that collective monologue is a normal part of development and eventually disappears as children become more socially aware. However, some psychologists believe that collective monologue can be a sign of autism or other developmental disorders.

Therefore Jean Piaget is the correct option.