What characteristic defines the 'concrete operational' stage in Piaget's theory?

The defining characteristic of the 'concrete operational' stage in Piaget's theory is the ability to think logically about concrete events. This stage typically occurs between the ages of 7 and 11 and is marked by the development of logical thinking that is directly tied to tangible objects and real-life situations. Children in this stage can perform operations such as classification and serialization, which involve organizing and categorizing objects based on shared characteristics and understanding the concept of order.

During this period, children become capable of understanding the concept of conservation—the understanding that quantity does not change even when its shape does—demonstrating their logical reasoning about physical objects and the relationships between them. Unlike earlier stages, where thinking is dominated by appearances, the concrete operational stage allows for more structured reasoning, although it still relies heavily on concrete, tangible experiences rather than abstract or hypothetical scenarios.

This logical thinking ability represents a significant step in cognitive development, bridging the gap between egocentric thinking of the preoperational stage and the more abstract thinking that develops in the subsequent formal operational stage.