David A. Kareken, Ruben C. Gur, Andrew J. Saykin; Reading on the Wide Range Achievement Test-Revised and parental education as predictors of IQ: comparison with the Barona formula. Arch Clin Neuropsychol 1995; 10 (2): 147-157. doi: 10.1093/arclin/10.2.147
It is frequently necessary in research and clinical evaluations to obtain estimates of premorbid intelligence (IQ) which are separate from measured IQ. There is evidence that word reading may be useful in this aim. In order to determine the potential of the Wide Range Achievement Test-Revised (WRAT-R) reading subtest (READ) as an estimate of premorbid IQ, the present study examined the relationship between READ and IQ in healthy subjects. Consistent with other findings, READ accounted for a significant amount of variance in Verbal, Performance, and Full Scale IQ. Race and parental education, the latter being a variable not previously examined in this literature, accounted for incrementally valid variance in IQ beyond READ. The predictive power of these variables compares favorably with estimates made by the Barona IQ estimation formula, which uses only demographic information.