Final answer:
The preoperational stage is the second stage of Piaget's cognitive development theory, occurring between ages 2 and 7, characterized by symbolic thinking, language use, and egocentric thought but a lack of conservation understanding and logical thought processes.
Step-by-step explanation:
The preoperational stage is the second of Jean Piaget's stages of cognitive development, occurring approximately between the ages of 2 and 7 years old. During this time, children start to engage in symbolic play and learn to manipulate symbols; a stick can become a sword, and a child can imagine they are a brave knight. This stage is marked by the beginning of the use of language and the development of memory and imagination. Children think in very concrete terms and struggle with understanding the concept of conservation—the idea that objects can change in shape or appearance while still maintaining the same properties.
For example, if one child receives a whole pizza slice and another child receives the same amount of pizza but cut into several pieces, the child in the preoperational stage may incorrectly believe that the child with more pieces has more pizza overall. These children are unable to perform mental operations such as understanding that dividing an object into parts does not change its mass or volume, which is why they cannot yet grasp the conservation of quantity.