Performance IQ

Performance IQ is a measure of intelligence that does not require the use of words or language and is associated with the Wechsler Intelligence Scales. When David Wechsler developed his IQ test in 1939, he divided it into two components: tasks that required mainly verbal abilities and tasks that required mainly perceptual-manipulative skills. The Performance IQ can be considered mainly a measure of visual-spatial processing, novel problem solving, attentiveness to visual detail, and visual-motor integration and speed. Recent editions of the Wechsler scales have broken down the Performance IQ into a perceptual organization component and a processing speed component. The perceptual organization scale most closely represents what has been traditionally thought of as Performance IQ.

Another way of thinking about Performance IQ is that it is that aspect of intelligence that does not depend upon experience and learning, sometimes referred to as fluid intelligence. Because experience is not heavily weighted, Performance IQ is considered to be relatively free of cultural bias. For this reason, the Performance IQ is sometimes used in place of the Full Scale IQ with minorities and individuals whose first language is not English as the overall indicator of intelligence. Although the research is far from definitive, there is some indication that skills measured by Performance IQ tend to decline with age, whereas those measured by Verbal IQ tend to stay the same or actually increase. Attempts to tie Performance IQ to the right hemisphere of the brain and Verbal IQ to the left hemisphere generally have not been successful.