L.S. Vygotsky's Principle "One Step in Learning — A Hundred Steps in Development": In Search of Evidence

On the basis of L.S. Vygotsky's published works the paper attempts to trace the dynamics of his concepts of child development and to provide evidence supporting Vygotsky's statement that one step in learning equals a hundred in development, which is one of the key principles of cultural-historical theory in its application to child development. This statement is put in a row with two other major principles: one arguing that learning precedes development and the other referring to the zone of proximal development. The paper outlines a multivector model of the zone of proximal development as one of the conceptual tools of the reflective and activity approach to helping children overcome learning difficulties and promoting their development. The paper also describes a case study in which an orphan child with a disability received psychological and educational support that obviously contributed to the child's development. It is argued that L.S. Vygotsky's idea of the specific relationship between learning and development has fundamental theoretical and practical implications, in particular, for working with children with special needs.