There are a number of psychological tests used to measure intellectual ability in children, but there are a limited number that are available for preschool-aged children.
Although measurement of skills in children prior to the start of formal schooling is often difficult, there are a few assessments that allow for the measurement of inherent cognitive abilities in children as young as 2 years old.
Wechsler Preschool and Primary Scale of Intelligence
The Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition, called the WPPSI-IV, measures cognitive development in children aged 2 years, 6 months to 7 years, 7 months. This scale measures cognitive development in several areas.
For children aged 2 years, 6 months to 3 years, 11 months, cognitive development is measured through verbal comprehension, visual-spatial and working memory skills. Children aged 4 years, 0 months to 7 years, 7 months are measured in these same three areas along with fluid reasoning and processing speed skills. These skill areas together create the full scale intelligence quotient, or full scale IQ.
The Stanford-Binet Intelligence Scales, Fifth Edition, called the Stanford-Binet 5, is a cognitive assessment for individuals aged 2 and older, including adults. This scale measures five factors of cognitive abilities, which includes fluid reasoning, knowledge, quantitative reasoning, visual-spatial processing, and working memory.
This measure provides scores for each cognitive ability area as well as a full scale IQ. This assessment includes numerous manipulatives, so caution should be exercised when using this with young children.
Differential Ability Scales-II
The Differential Ability Scales, Second Edition, called the DAS-II, is a measure of cognitive ability that can be used with children from 2 years, 6 months to 17 years, 11 months. Abilities that are measured include processing, visual recognition/matching, naming speed, number concepts, immediate/delayed recall, and verbal/visual working memory.
Each area provides an ability score while the areas combined results in a General Conceptual Ability score, an overall measure of intelligence. The Early Years Cognitive Battery is used with children 2 years, 6 months to 6 years, 11 months, and it examines nonverbal, verbal and spatial reasoning, using four or six subtests depending on the child’s age.
Kaufman Assessment Battery for Children-II
The Kaufman Assessment Battery for Children, Second Edition, called the KABC-II, measures cognitive ability in children between the ages of 3 and 18 years of age. It is thought to provide a more culturally unbiased assessment of cognitive skills for children of various backgrounds.
It relies less on verbal instructions, allowing language to have less influence on performance. The assessment itself measures sequential processing, simultaneous processing, planning, learning, and knowledge through various subtests. The assessment of crystallized knowledge may be excluded for children whose ability to demonstrate knowledge would be unfairly impacted by cultural concerns.