The intelligence tests developed by David Wechsler have been updated over time and are now categorized into three main versions used today: the Wechsler Adult Intelligence Scale-fourth edition (WAIS-IV) for adults, the Wechsler Intelligence Scale for Children (WISC-V) for school-aged children, and the Wechsler Preschool and Primary Scale of Intelligence—IV (WPPSI-IV) for young children.