Leonid Vladimirovich Zankov (Russian: Леонид Владимирович Занков; 23 April 1901 – 27 November 1977) — was a Soviet psychologist and defectologist, a member of Vygotsky Circle [1] and a major administrator of scientific research in the Soviet Union.. Zankov specialized in the psychology of memory, psychology of abnormal development (defectology), and educational ...