Hockenbury Discovering Psychology 5th txtbk

388 CHAPTER 9 Lifespan DevelopmentJean Piaget Swiss psychologist Jean Piaget(1896–1980) viewed the child as a little scientist,actively exploring his or her world.Much of Piaget’s theory was based on hiscareful observation of individual children,especially his own children.Fuzzy Tastes Different! During the sensorimotorstage, infants and toddlers rely ontheir basic sensory and motor skills toexplore and make sense of the worldaround them. Piaget believed that infantsand toddlers acquire very practicalunderstandings about the world as theytouch, feel, taste, push, pull, twist, turn,and manipulate the objects they encounter.Ellis, 1996). As the child assimilates new information and experiences, he eventuallychanges his way of thinking to accommodate new knowledge (Miller, 2002).Piaget believed that these stages were biologically programmed to unfold attheir respective ages (Flavell, 1996). He also believed that children in every cultureprogressed through the same sequence of stages at roughly similar ages. However,Piaget also recognized that hereditary and environmental differences could influencethe rate at which a given child progressed through the stages (Fischer &Hencke, 1996; Wadsworth, 1996).For example, a “bright” child may progress through the stages faster than a childwho is less intellectually capable. A child whose environment provides ample andvaried opportunities for exploration is likely to progress faster than a child who haslimited environmental opportunities. Thus, even though the sequence of stages isuniversal, there can be individual variation in the rate of cognitive development.The Sensorimotor StageThe sensorimotor stage extends from birth until about 2 years of age. During thisstage, infants acquire knowledge about the world through actions that allow themto directly experience and manipulate objects. Infants discover a wealth of very practicalsensory knowledge, such as what objects look like and how they taste, feel,smell, and sound.Infants in this stage also expand their practical knowledge about motor actions—reaching, grasping, pushing, pulling, and pouring. In the process, they gain a basicunderstanding of the effects their own actions can produce, such as pushing a buttonto turn on the television or knocking over a pile of blocks to make them crashand tumble.At the beginning of the sensorimotor stage, the infant’s motto seems to be, “Outof sight, out of mind.” An object exists only if she can directly sense it. For example,if a 4-month-old infant knocks a ball underneath the couch and it rolls out ofsight, she will not look for it. Piaget interpreted this response to mean that to theinfant, the ball no longer exists.However, by the end of the sensorimotor stage, children acquire a new cognitiveunderstanding, called object permanence. Object permanence is the understandingthat an object continues to exist even if it can’t be seen. Now the infant will activelysearch for a ball that she has watched roll out of sight. Infants gradually acquire anunderstanding of object permanence as they gain experience with objects, as theirmemory abilities improve, and as they develop mental representations of the world,which Piaget called schemas (Berthier & others, 2000).The Preoperational StageThe preoperational stage lasts from roughly age 2 to age 7. In Piaget’s theory, theword operations refers to logical mental activities. Thus, the “preoperational” stageis a prelogical stage.