During this stage senses, reflexes, and motor abilities develop rapidly. Intelligence is first displayed when reflex movements become more refined, such as when an infant will reach for a preferred toy, and will suck on a nipple and not a pacifier when hungry. Understanding of the world involves only perceptions and objects with which the infant has directly experienced. Actions discovered first by accident are repeated and applied to new situations to obtain the same results.
(Birth To 2 Years)