Final answer:
Pre-operational thinking is the second stage of Piaget's theory of cognitive development, characterized by egocentrism, conservation difficulties, and the inability to perform mental operations.
Step-by-step explanation:
Pre-operational thinking is the second stage of Piaget's theory of cognitive development, which occurs from approximately 2 to 7 years old. It is characterized by egocentrism, conservation difficulties, and the inability to perform mental operations. Egocentrism refers to the child's inability to see things from another person's perspective.
Conservation difficulties mean that children in this stage struggle to understand that the quantity of something remains the same even if its appearance changes. Lastly, pre-operational children cannot mentally manipulate information, which means they lack the ability to perform logical operations. An example of this is a child not understanding that redistributing slices of pizza does not change the amount of pizza.