The relationship between speed of processing and intelligence in young children

Processing speed is associated with intelligence, but the literature is not clear either on the definition of processing speed or on how it contributes to individual differences in intelligence. The present study investigated... [ view full abstract ]

Processing speed is associated with intelligence, but the literature is not clear either on the definition of processing speed or on how it contributes to individual differences in intelligence. The present study investigated the relations among age, speed of processing, control of processing, and intelligence, fluid and crystallized. A total of 157 children from 7 through 18 years were tested in a test battery consisting of two simple reaction time tasks, a Go/no-go reaction time task, a letter-matching task, and the Wechsler Abbreviated Scale of Intelligence (WASI). The present results indicate that speed of processing improves throughout the age range from 7 through 18 years; it reflects bottom-up sensory control processes which through top-down control processes exert effects on intelligence. Diffusion modeling showed that individual differences in drift rate of elementary cognitive tasks (ECTs) predict individual differences in intelligence. Therefore, both bottom-up and top-down influences of the ECTs on IQ make unique contributions to the prediction of IQ variability.