According to Piaget, at which cognitive development stage do children comprehend only one dimension at a time?

In the context of Piaget's stages of cognitive development, children in the preoperational stage, which typically occurs between ages 2 and 7, focus on a singular dimension of information. This characteristic is evident in their thinking processes, which are often egocentric and dominated by intuition rather than logical reasoning. During this stage, children struggle with understanding the concept of conservation and are unable to manipulate or understand multiple dimensions of a problem simultaneously.

For example, when presented with two rows of coins, if one row is spread out while the other remains in a compact form, a child in the preoperational stage will likely say that the longer row has more coins, demonstrating their difficulty in considering multiple dimensions such as length and quantity at the same time. This lack of ability to think logically about transformations and relationships contributes to their focus on one aspect of a situation.

The other stages mentioned each represent different cognitive abilities; in the concrete operational stage, children begin to understand multiple dimensions, while the formal operational stage includes abstract thinking. The sensorimotor stage, earlier in development, focuses on physical interaction with the environment rather than cognitive dimensions. Thus, the preoperational stage is where the limitation to comprehending one dimension at a time is most prominently observed