This is the first part of the research that was carried out 70 years ago under the guidance of L.S. Vygotsky and that belongs to the set of studies devoted to the experimental verification of the hypothesis of dynamic relation between speech and thought in ontogenesis. The main task of the research was to explore the psychological structure of the processes that underlie practical intellectual operations; their relation to speech in the process of development and dissociation. Forty normally developing children aged 3 to 7, six children with oligophrenia and four children with amnesic aphasia took part in this study. The authors used the experimental-genetic method. As a result of the research, the stages of thought and speech development were described. In particular, the authors described a type of speech that is not directly related to the intellectual operations that proceed at the same time. On a certain stage of development the relation between speech and thought become more complex. At first, speech reflects the behavior; then it plans and organizes it. The planning function of speech appears initially as the external activity («egocentric» speech), and only in further development it becomes internal.
For citation:Bozhovich L.I. Speech and practical intellectual activity of a child (an experimental-theoretical study). Kul'turno-istoricheskaya psikhologiya = Cultural-Historical Psychology, 2006. Vol. 2, no. 1, pp. 65–76. (In Russ., аbstr. in Engl.)