Research on executive functioning (EF) has been predominantly focused on preschool children. This paper outlines why it is important to examine EF throughout childhood and across the lifespan:examining EF in older children can address the question of whether EF is a unitary construct. much of the development of EF, especially working memory, shifting, and planning, occurs after age 5.important applications of EF research concern the role of school-age children’s EF in various aspects of school performance, as well as social functioning and emotional control. The prefrontal cortex (PFC) is critical to the planning, organization, and regulation of cognition and behavior. Executive function (EF) serves as an umbrella term to encompass the goal-oriented control functions of the PFC. Relatively complex neuropsychological instruments such as the Wisconsin Card Sorting Test (WCST) were first employed to evaluate frontal lobe functioning and later to assess EF. Research with a focus on preschoolers is great, because such work identifies the very beginnings of each component of EF. Also, as it is needed to work with simplified tasks, suitable for young children, it is possible to assess a single EF component, thus avoiding the problem of task impurity. Finally the focus on preschoolers has revealed important relations between EF and theory of mind. However, assessing EF in school-age children allows us to ask questions that cannot be answered in research with preschoolers. Research on further changes in the development of each EF component and in the relations among the components during later childhood and adolescence would not only clarify EF as a construct but also provide insight into processes underlying the development of EF. Furthermore, significant improvements in EF tasks occur during the school years. It is, therefore, important to examine EF in school-age children in order to get a developmental picture...