"Lev Vygotsky’s (1896-1934) main relevance to constructivism derives from his theories about language, thought, and their mediation by society. He holds the anti-realist position that the process of knowing is rather a disjunctive one involving the agency of other people and mediated by community and culture. He sees collaborative action to be shaped in childhood when the convergence of speech and practical activity occurs and entails the instrumental use of social speech. Although in adulthood social speech is internalized (it becomes thought), Vygotsky contends, it still preserves its intrinsic collaborative character. "
(Gellof Kanselaar, 2002)
Kanselaar, Gellof, (2002). Unpublished paper about (Socio-)Constructivism.