ABSTRACT
Since the 1962 publication of Vygotsky’s Thought and Language in the U.S., a number of North American and European investigators have conducted systematic observations of children’s private speech, giving substantial support to his major hypotheses (see reviews by Fuson, 1979 and Berk, this volume). The findings have supported Vygotsky’s original claim that private speech, as a tool of thought, constitutes an important link between the social and psychological worlds of the individual, a most unique bridge between mind and society (Vygotsky, 1930–1935/1978). Through the increased use of private speech in development, the language that mediates social interaction is gradually internalized to become a major vehicle for self-regulation (Diaz, 1986a; Diaz, Neal, & Amaya-Williams, 1990). Moreover, the use of private speech seems to transform the course of cognitive development, by allowing executive and metacognitive control over cognitive operations in the realms of memory (Flavell, Beach, & Chinsky, 1966), attention (Berk, 1986), and problem-solving (Azmitia, this volume; Wertsch, McNamee, McLane, & Budwig, 1980).
