Piaget and Vygotsky Theories of Cognitive Development.
Everyday life is characterized by conscious purpose. From reaching for food to designing an experiment, our actions are directed at goals. This purpose reveals itself partly in our conscious awareness and partly in the organization of our thoughts and actions. Cognition is the process involved in thinking and mental activity, such as attention, memory and problem solving. Much past and present theory has marked the match between the significant structure of language and the structure of an internal code or "language of thought" (Langer, 1969). .
There are those that say that Jean Piaget was the first to take children's thinking seriously. Although Piaget never thought of himself as a child psychologist, his real interest was epistemology, the theory of knowledge, which, like physics, was considered a branch of philosophy until Piaget came along and made it a science (Lavatelli, 1985). Children and their reasoning process fascinated Piaget. He began to suspect that observing how the child's mind develops might discover the key to human knowledge. Piaget's insight opened a new window into the inner workings of the mind. Jean Piaget has made major theoretical and practical contributions to our understanding of the origins and evolution of knowledge (Evans, 1973). .
In his work Piaget identified stages of mental growth. He theorized that all children progressed through stages of cognitive development. He discovered that children think and reason differently at different periods in their lives. Piaget believed that everyone passed through a sequence of four qualitatively distinct stages. They are sensorimotor, preoperational, concrete operational and formal operational (Encarta). In the sensorimotor stage, occurring from birth to age 2, the child is concerned with gaining motor control and learning about physical objects. This stage promotes that thought is based primarily on action.