Piaget's developmental stages are modes of normal intellectual development. There are four different phases. The stages begin in childhood and continue into adulthood. The stages include things like judgment, thinking, and knowledge in infants, children, adolescents, and adults. These four stages are named after Jean Piaget, a developmental biologist and psychologist. Piaget recorded the intellectual abilities and development of infants, children, and adolescents. The four different phases of Piaget's developmental stages are sensorimotor, preoperational, concrete operational, and formal operational. Sensorimotor is from birth to twenty-four months of age. The preoperative phase, or infancy, includes from eighteen months to early childhood, at seven years of age. The concrete operation is from seven to twelve years. Finally, the formal operation is adolescence to adulthood. Sensorimotor is the early stages of Piaget's developmental stages. Newborns are only aware of what is directly in front of them. They tend to focus more on what they are doing, what they see and what is happening at that moment. Children are constantly learning new things and experimenting, such as; throwing objects, putting hands in mouth, shaking objects. This is what you call learning through trial and error. Kids don't know any better, so this is pretty much the only way they learn. Once babies get a little older, around seven to nine months, they begin to realize that even if objects aren't seen, they still exist. This means that their memory is starting to develop. Towards the end of the sensorimotor stage, children begin to achieve other important things such as the ability to speak and understand language. The... center of the card... people age from childhood until death. Even if the stages stop at the fourth, this does not mean that intellectual learning stops. Adulthood extends from the moment you exit the concrete operational phase until it is no longer impossible for you to learn. Although some adults stop developing intellectually, others do not. Continued intellectual development in adults depends solely on the accumulation of knowledge in a person. I believe that what Piaget says about his stages of development is very accurate and quite logical. Works CitedWood, K. "Piaget's Stages of Cognitive Development," in M. Orey Emerging perspectives on learning, teaching, and technology, 2001.PBS.org: "Piaget describes stages of cognitive development 1923-1952." Huitt, W. "Piaget's Theory of Cognitive Development. Interactive Educational Psychology," 2003