Lev Vygotsky (1896-1934) developed a sociocultural theory of cognitive development that provides the most important alternative and complement to Piaget's constructivism. Despite dying of tuberculosis at age 37, Vygotsky produced a body of work that has become increasingly influential. His central insight was that cognitive development is not primarily an individual achievement but a social process — higher mental functions develop through interaction with more capable others and are mediated by cultural tools, especially language.
Key Concepts
The zone of proximal development (ZPD) is the difference between what a child can do independently and what they can do with guidance from a more skilled partner (parent, teacher, peer). This zone represents the optimal space for instruction — tasks within the ZPD are challenging enough to promote growth but achievable with support. Scaffolding (a term inspired by Vygotsky but coined by Wood, Bruner, and Ross) describes the temporary support provided by a more knowledgeable partner, gradually withdrawn as the learner becomes more competent.
Vygotsky proposed that language transforms thinking. Private speech (children talking to themselves during problem solving) is not egocentric (as Piaget thought) but serves a self-regulatory function — the child is using language to guide their own thinking. Private speech develops from social speech (conversation with others) and eventually becomes internalized as inner speech (verbal thought). This developmental sequence — from social to individual, from external to internal — captures Vygotsky's general law of development: every higher mental function appears first between people (interpsychological) and then within the individual (intrapsychological).