ABSTRACT
This kernel of this article is to provide in-depth understanding of the developmental psychology concepts of Jean Piaget and Lev Vygotsky, who have laid the foundation for extensive research and scope for refinement their theories in developmental psychology, primarily in child and adolescent growth. The Piagetian stages, criticisms and limitations of Piaget’s stages cognitive development, and critical works of Neo-Piagetians have been highlighted. Parallelly, Vygotsky’s Socio-cultural theory, limitations and criticisms of his theory, and the significant contributions of Neo-Vygotskians in refining and re-defining Vygotsky’s works to fill the gaps in his research, have also been shed light on. Finally, an extensive comparison of the Swedish and the Russian Psychologist’s theories is done, to grasp the concepts of the two clearly, and to better understand how teachers, parents, and psychologists alike can permutate and combine the concepts and practices of the two-most fundamental theories of developmental psychology