Step 1: Identify the core question: The prompt requires identifying the developmental theorist whose cognitive development theory emphasizes social interaction, culture, and language.
Step 2: Analyze the options:
(A) Lev Vygotsky: His Sociocultural Theory posits that social interaction and language are crucial for cognitive development. Key concepts like the Zone of Proximal Development (ZPD) and the role of language in shaping thought align with the prompt's focus. This is a strong candidate.
(B) Newcombe and Huttenlocher: These are contemporary researchers focusing on spatial development.
(C) Piaget (Jean Piaget): Piaget's constructivist theory centers on individual interaction with the physical world, with less emphasis on language or social instruction.
(D) Kohlberg (Lawrence Kohlberg): His theory addresses moral development, not cognitive development as the primary focus.
Step 3: Conclude: Lev Vygotsky's theory most accurately reflects the emphasis on social factors and language in cognitive development.