Cognitive Development

Piaget is considered the father of cognitive development because his studies were the first to examine children's thinking and because he offered a comprehensive theory of how cognition changed over time. His theory of cognitive development was based on data from a series of experiments and interviews of children (including his own) that explored their thinking in a variety of contexts. Piaget's theory consisted of four stages of development from birth to adolescence: sensorimotor, preoperational, concrete operational, and formal operational.