The famous Swiss psychologist, Jean Piaget (1896-1980), stressed that children actively construct their own cognitive worlds; information is not just poured into their minds from the environment. Piaget believed that children adapt their thinking to include new ideas. He thought that assimilation (which is an individual's incorporation of new information into their existing knowledge) and accommodations (an individual's adjustment to new information) operate even in the very young infant’s life. Newborns reflexively suck everything that touches their lips (assimilation), but, after several months of experience, they construct their understanding of the world differently. Some objects, such as fingers and the mother’s breast, can be sucked, but others, such as fuzzy blankets, should not be sucked(accommodation).
Piaget believed that we go through four stages in understanding the world. Each of the stages is age-related and consists of distinct ways of thinking.
