Читать книгу Lifespan Development - Tara L. Kuther - Страница 361

“You ruined it!” cried Johnson after his older sister, Monique, placed a triangular block atop the tower of blocks he had just built. “No, I just put a triangle there to show it was the top and finish it,” she explains. “No!” insists Johnson. “OK, I’ll take it off,” says Monique. “See? Now it’s just how you left it.” “No. It’s ruined,” Johnson sighs. Johnson continued to be upset after his sister removed the triangular block, not realizing that by removing the block, she has restored the block structure to its original state. Young children’s thinking is characterized by irreversibility, meaning that they do not understand that reversing a process can often undo it and restore the original state.

Preoperational children’s irreversible thinking is illustrated by their performance on tasks that measure conservation, the understanding that the physical quantity of a substance, such as number, mass, or volume, remains the same even when its appearance changes. For example, a child is shown two identical glasses. The same amount of liquid is poured into each glass. After the child agrees that the two glasses contain the same amount of water, the liquid from one glass is poured into a taller, narrower glass and the child is asked whether one glass contains more liquid than the other. Young children in the preoperational stage reply that the taller narrower glass contains more liquid. Why? It has a higher liquid level than the shorter, wider glass has. They center on the appearance of the liquid without realizing that the process can be reversed by pouring the liquid back into the shorter, wider glass. They focus on the height of the water, ignoring other aspects such as the change in width, not understanding that it is still the same water. Figure 7.4 illustrates other types of conservation problems.

Description

Figure 7.4 Additional Conservation Problems

Characteristics of preoperational children’s reasoning are summarized in Table 7.2.

Table 7.2