Jean Piaget was born in Neuchâtel, Switzerland, on August 9, 1896. Many psychologists consider him to be the most influential developmental psychologist of the twentieth century. He made detailed observations of children's activities, talked to children, listened to them talking to each other, and devised and presented many tests of children's thinking.
It was Piaget who founded genetic epistemology, the study of the development of knowledge. Originally based on the observations he made of his own children, he concluded that younger children's intelligence is both qualitatively and quantitatively different to that of older children's. Piaget suspected that the way that we are able to form and deal with concepts changes as we move from childhood to adolescence.
Piaget's theory of cognitive development focuses on the organisation of intelligence and how it changes as children grow, and he identified a number of distinct stages of intellectual development (sensorimotor, pre-operational, concrete operational and formal operational). He suggested that children progress through each stage in turn, in sequence. However, it has been argued that it is possible for children to reach later stages without progressing through earlier ones (Horn, 1976) an example of this is some children walk without ever crawling. The notion of "stages" as suggested by Piaget is disputed and has both supporters, such as Flavell, 1971, and opponents, such as Sternberg, 1990.
Some researchers have been critical about Piaget's "stages" theory, arguing that discontinuous, step-like changes in cognitive development suggested by stages are improbable and that development proceeds in a continuous style (Keating, 1980). Bee (1995) considers that development is a gradual process where skills, which existed in an earlier age in a more elementary form, are progressively enhanced.
Although the validity of "stages" has been accepted by some researchers, it has been suggested that there are cultural differences in the rates of development in various cognitive domains. It is thought that Piaget excluded other people's involvement to children's cognitive development, seeing children mainly self-determining and secluded in their construction of knowledge of the physical world (Meadows 1995).
Piaget believed that children in the sensorimotor stage (approximately birth to two years) experience the world generally through corporeal activity and immediate perceptions, without thought, as adults know it. He alleged that until approximately eight months of age, a child has no concept of object permanence. During this time, a baby would adopt and "out of sight, out of mind" approach, and would not attempt to search for a previously visible object that was placed out of sight as they watched. A lot of contemporary research into infant cognition gives evidence to show that Piaget underestimated some of the cognitive abilities of babies. Bower (1981) challenged some of...