T. G. Wiesel emphasized the importance of differentiating different types of developmental disorders at an early age in order to avoid confusion and to accurately determine the type of support or treatment that is appropriate for each child. This concept is based on the assumption that developmental disorders in children, such as autism spectrum disorders, attention disorders, dyslexia, or mental retardation, may have similar common behavioral manifestations but differ in their neuropsychological mechanisms. Therefore, early differential diagnosis becomes necessary to understand the nature of the disorder and develop an individual treatment plan. This model is based on careful observation of developmental indicators and the use of qualitative assessment tools to detect subtle differences between disorders. The ultimate goal is to prevent misgeneralization or inaccurate diagnosis that could lead to inadequate or delayed intervention. The earlier and more differentiated the diagnosis, the higher the chances of successful therapeutic and rehabilitation intervention.