Final answer:
In the preoperational stage, children develop the capacity for symbolic thought, evidenced by their engagement in pretend play. However, they cannot perform mental operations, including understanding the concept of conservation, and they exhibit egocentrism. Gradually, they make progress in language, comprehend basic time concepts, and develop a theory-of-mind.
Step-by-step explanation:
One of the major developments during the preoperational stage of cognitive development, spanning approximately from 2 to 7 years old, is the ability for children to use symbols to represent words, images, and ideas. This is evident when children engage in pretend play, signifying the burgeoning capacity for symbolic thinking. For instance, a child using a stick as a sword shows their ability to replace real objects with symbols to convey meaning.
However, there are several problems that persist during this stage. Children lack the ability to perform mental operations, which means they can't undertake logical manipulation of information. An example of this limitation is the concept of conservation, where children at this stage do not understand that the quantity of something remains the same despite changes in its shape or arrangement, as illustrated by the pizza slices scenario with Keiko and Kenny. Furthermore, children also exhibit egocentrism, struggling to comprehend that others have different viewpoints and feelings.
Despite these limitations, children in the preoperational stage make considerable strides in language acquisition and are able to grasp basic time concepts and sequencing. As they develop, their curiosity flourishes, often demonstrated through a multitude of 'why' questions, signaling cognitive growth. Over time, they begin to develop a theory-of-mind (TOM), slowly understanding that other people have different thoughts and beliefs.