IQ and neuropsychological predictors of academic achievement

Word reading and math computation scores were predicted from Wechsler Abbreviated Scale of Intelligence Full Scale IQ, 10 neuropsychological tests, and parent attention deficit hyperactivity disorder (ADHD) ratings in 214 general population elementary school children. IQ was the best single predictor of achievement. In addition, Digit Span contributed significantly to reading prediction, and the Developmental Test of Visual-Motor Integration (VMI) and Coding contributed to math prediction. The remaining neuropsychological test scores did not significantly improve achievement prediction. Exploratory factor analysis yielded a general ability factor (comprising the four IQ subtests, Digit Span, VMI, reading, and math), five factors made up solely of subtests from single measures (Wisconsin Card Sorting Test, Stroop Color and Word Test, Gordon Diagnostic System, California Verbal Learning Test, and ADHD ratings), a factor consisting of Grooved Pegboard Test and Coding, and a factor consisting of Symbol Search and Animal Naming Test.