The function of signs in the development of higher mental processes
pp. 539-550
in: Robert W. Rieber, David K. Robinson (eds), The essential Vygotsky, Berlin, Springer, 2004Abstract
We have considered some of the complex behavior of the child and have concluded that in a situation connected with the use of tools, the behavior of a small child differs substantially and in a major way from the behavior of the human-like ape. We could say that in many ways, it is characterized by an opposite structure and that instead of a complete dependence of the operation with tools on the structure of the visual field (as in the ape), in the child we observe a significant emancipation from it. Due to the participation of speech in the operation, the child acquires an incomparably greater freedom than is observed in the instrumental behavior of the ape; the child has the possibility of resolving the practical situation by using tools that are not in the direct field of his perception; he controls the external situation with the help of preliminarily mastering himself and preliminarily organizing his own behavior. In all of these operations, the very structure of the mental process changes substantially; direct actions on the environment are replaced by complex mediated acts. Speech included in the operation was the system of psychological signs that acquired a very special functional significance and resulted in a complete reorganization of behavior.