The ZPD is a theory that Vygotsky created explaining learning development in children. The lower level of ZPD, known as the actual developmental level, is what the child knows independently, without help. However, the upper level of the ZPD is what the child does not know without help. The child needs assistance in order to reach this level of the ZPD. For example, Billy could figure out how to tie his shoes on his own, without help. This demonstrates the lower level of ZPD. Meanwhile, Sarah does not know how to tie her shoes on her own, and needs help to get to the upper level of the ZPD. Her parents show her how, and she then reaches the upper level of ZPD.
Lev Vygotsky was born November 17, 1896, and died on June 11, 1934. He lived in Russia, and was one of the biggest contributors to the field of developmental psychology. He had several theories, the Social-Cultural theory, the Zone of Proximal Development, and more. Many of his writings have been translated, but some have yet to be translated to English.
"Sociology;"
-The study of society and social effects on people. This science studies how different types of people interact, and what types of norms are expected in different cultures.
The Social-Cultural Theory suggested that children only learn and develop with interactions between different people, as well as themselves. These interactions are known as interpsychological and intrapsychological. Inter being interacting with different people, and intra meaning interacting with themselves.