Initially the study of lifespan development rose due to Darwin’s desire to understand human evaluation (Boyd & Bee, 2006). Developmental psychology is concerned with the changes of people during their life span including motor skill changes, problem solving changes, moral understanding changes, but it is originally concerned with these changes during infancy and childhood (Boyd & Bee, 2006). Without any doubts, Jean Piaget (1896-1980) and Lev Vygotsky (1896-1934), are two major contributors who have affected developmental psychology with their theories on human development. According to Lerman (1996), Piaget and Vygotsky belong to two different traditions; Piaget belongs to the constructivism perspective that sees learning as construction and Vygotsky to the activity theory perspective that sees learning as an appropriation.
According to Piaget, cognitive development results from the development of the brain, acquiring new abilities and experiences, thus he separated development into stages (as cited in Santrock, 2008). Piaget developed four stages the sensori-motor stage (0-2 years) where the infant is trying to make sense of the world, and acquires the development of object permanence (Shaffer & Kipp, 2007). The pre-operational stage (2-7 years) where language development, animism, egocentrism and the use of symbols hallmark this stage (Shaffer &Kipp, 2007). The concrete operational stage (7-11 years) where children start classifying objects and are able to conserve and think logically about objects and events (Shaffer & Kipp, 2007). And the formal operational stage (11 years and beyond) where children develop hypothetico-deductive reasoning and imaginary audience and believe in the uniqueness of oneself and one’s experiences (Shaffer & Kipp, 2007).
On the other hand, Vygotsky developed his sociocultural theory