Page 37 - Demo

Prenatal and Childhood Development MODULE 10 167Preoperational StagePiaget defined the preoperational stage (from about age 2 to about age 6 or 7) as a time during which a child learns to use language but cannot yet think logically. If you show 5-year-olds two identical clear glass beakers, each with a cup of blue liquid in them, they%u2019ll know the beakers hold the same amount. However, if you then pour the contents of one beaker into a taller, narrower beaker, causing the water line to move up, the preoperational child will probably tell you the new beaker now holds more liquid. Although the different-sized beakers hold the same amount of liquid, 5-year-olds typically focus only on the height dimension. At this age, children lack an understanding of conservation, the principle that properties such as mass, volume, and number remain the same even if the object%u2019s form changes. Without this understanding, 5-year-olds do not have the cognitive skills to mentally pour the tall beaker%u2019s contents back into the regular beaker (Figure 10.8).(a) Objects placed in case (b) Screen comes up (c) Empty hand enters (d) One object removedThen either: possible outcome(e) Screen drops revealing 1 objector: impossible outcome(f) Screen drops revealing 2 objectsFIGURE 10.7 Early Object PermanenceWhen shown a numerically impossible outcome (there are still two objects after they watch one object being taken away), 5-month-old infants stare longer at the two objects, a finding that supports the development of object permanence far earlier than Jean Piaget assumed. (Research from Wynn, 1992.)preoperational stage In Piaget%u2019s theory, the stage (from about 2 to 6 or 7 years of age) during which a child learns to use language but cannot yet think logically.conservation The principle (which Piaget believed to be a part of concrete operational reasoning) that properties such as mass, volume, and number remain the same despite changes in the forms of objects.FIGURE 10.8 Conservation ProblemConservation is the principle that properties such as mass, volume, and number remain the same even if the object%u2019s form changes. The two beakers in the third panel clearly have the same amount of liquid, but a 5-year-old would probably not understand this conservation problem.Bianca Moscatelli/Worth Publishers%u00a9 Bedford, Freeman & Worth Publishers. For review purposes only. Do not distribute.