TY - JOUR AU - DeFries, J. AB - In order to test the hypothesis that the genetic etiology of reading disability differs as a function of IQ, composite reading performance data from 308 pairs of identical (monozygotic, MZ) twins and 440 pairs of fraternal (dizygotic, DZ) twins (254 same-sex and 186 opposite-sex) in which at least one member of each pair was classified as reading-disabled were subjected to multiple regression analysis (DeFries and Fulker, Behav Genet 15:467–473, 1985; Acta Genet Med Gemellol 37:205–216, 1988). In the total sample, heritability of the group deficit in reading performance (h g 2 ) was .61 (±.06). However, results of fitting an extended regression model to reading performance and IQ data suggested that the genetic etiology of reading disability differs as a linear function of IQ (p ≤ .04). When the basic regression model was fitted separately to data from twin pairs with Wechsler (Examiner's manual: Wechsler intelligence scale for children—revised, 1974; Examiner's manual: Wechsler adult intelligence scale—revised, 1981) Full Scale IQ scores in the upper and lower 25% of the sample, resulting estimates of h g 2 were .75 (±.12) and .50 (±.10), respectively (p ≤ .045). These results suggest that reading difficulties in children with a higher IQ are due substantially to genetic influences and may require intensive remediation efforts. TI - Differential Genetic Etiology of Reading Difficulties as a Function of IQ: An Update JF - Behavior Genetics DO - 10.1007/s10519-010-9349-x DA - 2010-03-24 UR - https://www.deepdyve.com/lp/springer-journals/differential-genetic-etiology-of-reading-difficulties-as-a-function-of-SbCUUXyjIY SP - 751 EP - 758 VL - 40 IS - 6 DP - DeepDyve ER -