In which age group is it most common for children to believe they are sick because they were bad?

Children in the preschool age group commonly engage in magical thinking, where they believe that their thoughts and actions can directly influence outcomes in their environment. This worldview leads them to associate their behavior with physical consequences, such as thinking they have become sick because they were "bad." During this developmental stage, children are beginning to understand the concept of cause and effect but often do so in a simplistic and self-centered manner. They may interpret illness as a punishment for wrongdoing, which is a reflection of their egocentric thinking and limited understanding of how health and illness actually work.

As children grow into the elementary age group, their cognitive abilities develop further, enabling them to understand illness more in terms of biology and external factors rather than personal behavior. Adolescents, meanwhile, are more capable of grasping complex relationships between actions and health, distancing them from the simplistic belief that being "bad" can cause physical ailments. Thus, preschoolers are the age group most likely to think they are sick due to their behavior, making this the correct choice.