What does the textbook list as possibly the most important intellectual accomplishment of the school-age child?

The ability to think logically and solve problems is often listed as one of the most important intellectual accomplishments of the school-age child by textbooks. This stage marks the development of concrete operational thinking, allowing children to understand concepts like conservation and classification. Additionally, the ability to understand the perspectives of others and engage in more complex social interactions is also highlighted as a crucial achievement during this period.