Abstract
The issue of sex differences in reading disability has been of recent interest in relation to sex ratios in families with reading disabled children and to possible sex biases in referred populations. Data from a study of 570 twins are used to develop alternative definitions of reading disability that vary in the manner to which sex effects are taken into account. These definitions include discrepancies between reading quotients and IQ, the use of the regression of reading onto IQ and chronological age/reading age differences. In each case the reading and spelling disability was defined either separately for the sexes or based upon the data for the sexes combined and with and without an IQ>90 exclusion criterion. The consequences of using the alternative definitions for prevalence, sex ratio and heritability are examined. The results demonstrate that the characteristics of reading disabled children vary with the way disability is defined. The excess of males seems to be a robust finding. Definitions that take into account differences in mean score for males and females reduce but do not eradicate the sex ratio. From the genetic analysis, there is no support for the suggestion that the genetic effect on reading is greater for females than males. It is concluded that the use of regression based procedures for identifying reading disability is desirable but that at present there is insufficient evidence to justify the adoption of separate regression procedures for the two sexes.
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Stevenson, J. Identifying sex differences in reading disability. Read Writ 4, 307–326 (1992). https://doi.org/10.1007/BF01027711
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DOI: https://doi.org/10.1007/BF01027711