The Language and Thought of the Child

Piaget's first major work — a study of children's language revealing that young children's speech is primarily egocentric (self-directed, not communicative) before becoming genuinely social.

Egocentric speech: young children talk primarily for themselves, not to communicate — a finding that challenged adult-centered assumptions about language. Stages of communicative development. The distinction between egocentric and socialized speech as a developmental sequence. Laid the groundwork for Piaget's later stage theory.