Reading ResponseSince the 20th century development in psychology has undergone various changes. Many early theorists have had an influence in the psychology field. Some of the notable theorists like Jean Piaget, Lev Vygotsky and Erick Erikson have had a great impact on child psychology. This paper is going to give a detailed report and contribution on the development stages, difference and similarities of the three theorists.The cognitive development process of Jean Piaget’s focuses on the stages of a child who transitions from one stage is followed by a sequence. Erick Erikson psychosocial development theory was developed later than Piaget’s. He dealt with the eight unique stages of a person’s life. Lev Vygotsky believes in the significance of socio-cultural environment in cognitive development. He emphasises on the instructions and social interactions function in development process.Erickson focuses on the whole development process, asserting how the environment engages with a child thereby influencing its development. Whereas Piaget’s theory of cognitive development takes an interest in a person’s thought process. He has special emphasis in an individual’s early years let’s say at the age of 12. Vygotsky has his different theory he proposes that in the roles of social interaction, a child’s development does not precede socialisation. The social structures and social relations have an impact in a person’s mental development and functions.The similarity in the three theories is that they all examine issues of development psychology all describing these developments through phases. Every theorist declaring that every stage has a distinguished challenge in the process of development. Thus, all successive stages correlate. To some extent that when one stage fails, the other stage also precipitates failure.These three theorists have contributed widely in the field of development psychology, As much as they drew inspirations from different sources in the 20th century.ReferenceMooney, C. G., & Amazon.com. (2013). Theories of childhood: An introduction to Dewey, Montessori, Erikson, Piaget, & Vygotsky. St. Paul, MN: Redleaf Press.