Piaget's stages of development are paths of normal intellectual development. There are four different stages. The stages begin as an infant and continue into adulthood. The stages include things like judgment, thinking, and knowing 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 stages of Piaget's stages of development are sensorimotor, preoperational, concrete operational, and formal operational. Sensorimotor development extends from birth until the age of twenty-four months. The preoperative period, which corresponds to early childhood, extends from eighteen months until early childhood, at seven years. Operational concrete lasts from seven to twelve years. Finally, the formal operation extends from adolescence to adulthood. Sensorimotor corresponds to the first stages of Piaget's development. Infants are only aware of what is directly in front of them. They tend to focus more on what they are doing, what they are seeing, and what is happening at the time. Infants are constantly learning new things and experimenting, such as: throwing objects, putting hands in mouth, shaking objects. This is what you call learning by trial and error. Infants don't know any better, so it's pretty much the only way they learn. Once infants grow a little older, around seven to nine months, they begin to realize that even though objects are not seen, they still exist. This means their memory is starting to develop. Towards the end of the sensorimotor stage, infants begin to acquire other important things like the ability to speak and understand language. The... middle of paper ... people age from childhood until death. Even though the steps stop at the fourth, that doesn't mean the intellectual learning stops. Adulthood extends from the time you leave the concrete operational phase until it is impossible for you to learn. Although some adults stop developing intellectually, others do not. The continued intellectual development of adults depends solely on the accumulation of knowledge in a person. I believe that what Piaget states in his stages of development is very precise and completely logical. Works Cited Wood, K. "Piaget's Stages of Cognitive Development", in M. Orey Emerging perspectives on learning, teaching, and technology, 2001.PBS.org: "Piaget describes the stages of cognitive development 1923-1952." Huitt, W. "Piaget's theory of cognitive development. Interactive educational psychology," 2003