During the 1920s–1930s while Piaget was developing his own theory, Vygotsky was an active scholar and at that time his theory was said to be “recent” because it was translated out of Russian language and began influencing Western thinking.
1920〜1930年代にピアジェが彼の理論を展開していたころ、ヴィゴツキーは活発な理論家であり、その時期に彼の理論はロシア語から翻訳され、西洋の思想に影響を与え始めていたため、「新たな理論」と呼ばれていた。