Bishop D V, Butterworth G E
Cortex. 1980 Oct;16(3):375-89. doi: 10.1016/s0010-9452(80)80039-6.
169 unselected children were given the WPPSI at 4 1/2 years and the WISC-R at 8 1/2 years. Retrospective data on perinatal risk factors and neurological disease in childhood were collected. Verbal-performance discrepancies at 4 1/2 years were not related to perinatal risk, childhood neurological disease, left-handedness or subsequent reading ability. A weak relationship was found between WISC-R verbal-performance discrepancies and perinatal history. At 8 1/2 years, VIQ correlated much more strongly with reading ability than did PIQ. Consequently, the relationship between verbal-performance discrepancy and specific reading retardation depends critically on how reading retardation is defined. Logical problems concerning the definition of specific reading retardation are discussed.