WISC--R verbal and performance IQ discrepancy in an unselected cohort: Clinical significance and longitudinal stability

This study examined children from an unselected birth cohort who had Wechsler Intelligence Scale for Children-Revised (WISC-R) verbal and performance IQ discrepancies that placed them beyond the 90th percentile. It was hypothesized that, relative to their cohort peers, these children would be characterized by greater frequency of perinatal difficulties, early childhood neurological abnormali-ties, health problems of neurological significance, and concussion. Additionally, it was hypothesized that such children would exhibit more behavior problems, lower academic achievement, and poorer motor skills. Generally, the null hypotheses were not rejected by the results. Longitudinal investiga-tion of the stability of the verbal and performance IQ discrepancy revealed that about 23 % of discrep-ant cases were discrepant at two or more ages. Depressed verbal IQ relative to performance IQ was found to be more common than the reverse pattern. Children with performance IQ greater than verbal IQ scored significantly lower than children for whom this pattern was reversed on measures of academic achievement. Results show that cautious interpretation is needed of verbal and perfor-mance IQ discrepancy in the general (nonneurological) assessment setting. Administration of the Wechsler Adult Intelligence Scale-Re-vised (WAIS-R; Wechsler, 1981) and the Wechsler Intelligence Scale Revised for Children (WISC-R; Wechsler, 1974) in the con-text of neuropsychological assessment has become widely ac-cepted clinical practice. Perhaps one of the most frequently in-terpreted measures obtained from these tests is the discrepancy between verbal IQ (VIQ) and performance IQ (P1Q). Initial evi-dence for wide VIQ-PIQ discrepancy as an indicator of cognitive pathology was established by a series of articles by Reitan an