Related article: tease apart just what aspects of brain anatomy and chemistry can help account for the gender skewing in mental disorders. Some studies are contradictory, and there is still more known about animals than about humans. Science http://www.sciencemag.org -------------------------------- Related Material: MEDICAL BIOLOGY: SEX DIFFERENCES READING DISABILITY The following points are made by M. Rutter et al (J. Am. Med. Assoc. 2004 291:2007): 1) Are boys more likely than girls to have reading disability? The answer to this question has both theoretical implications (with respect to possible causal mechanisms) and practical implications (with respect to service provision). If boys are truly more likely to have reading disability, this would direct research attention to uncovering the possible source of the sex difference. Also, the sex difference would offer a window into the understanding of the causal processes involved in the origins of developmental reading disability.(1) In addition, if boys are more prone to have reading disability, this should motivate educational programs Buy Angeliq to address boys' early emerging disability. Given that reading disability in childhood is associated with adjustment problems and long-term adverse outcomes in multiple life domains,(2) the elucidation of this disability should constitute a high priority. 2) Thirty years ago, epidemiological studies drew attention to the preponderance of male children with reading disability. Surveys both on the Isle of Wight and in an inner London borough(3) were consistent in showing that reading disability, whether assessed through group or individual tests, was substantially more frequent in boys than in girls. Moreover, the sex difference was evident whether reading disability was considered in terms of IQ-referenced (adjusted) specific reading retardation (in which reading was markedly lower than that predicted on the basis of age and IQ) or non-IQ-referenced general low achievement in reading. Thus, in the inner London sample of 10-year-olds, the rates of specific reading retardation on group tests were 16.9% in boys compared with 7.2% in girls. Using individual testing in those with positive screens on the group reading test, the rates were 4.6% vs 2.0%. The comparable data for Isle of Wight 10-year-old boys and girls were 8.6% vs 3.7% on group tests and 5.6% vs 2.9% on individual tests.3 3) When non-IQ-referenced reading disability was defined as performance at least 28 months behind population norms on either reading accuracy or reading comprehension, the male-female difference on group tests was 15.9% vs 7.2% in inner London, with 22.2% vs 15.6% on the basis of individual testing of those who had positive screens. The comparable Isle of Wight data were 8.6% vs 3.7% on group testing and 10.5% vs 6.1% on individual testing. The sample sizes in both cases were large: 1689 for the inner London 10-year-olds and 1142 for the Isle of Wight 10-year-olds. 4) Some 15 years later, in 1990, Shaywitz et al,(4) reporting on a sample of 414 children aged 7 to 8 years, drew attention to their finding that the sex ratio in their epidemiological study was very much less than that in their sample of children identified on the basis of school records. Among the children in second grade, the rates were 8.7% in boys vs 6.9% in girls, and 1 year later (at a mean age of 8.7 years), the comparison was 9.0% vs 6.0%. 5) The authors summarize the history of research on sex differences in reading disability and provide new evidence from four independent epidemiological studies about the nature, extent, and significance of sex differences in reading disability. In all 4 studies, the rates of reading disability were significantly higher in boys. The authors conclude: "Reading disabilities are clearly more frequent in boys than in girls."(5) References (abridged): 1. Rutter M, Caspi A, Moffitt TE. Using sex differences in psychopathology to study causal mechanisms: unifying issues and research strategies. J Child Psychol Psychiatry. 2003;44:1092-1115 2. Snowling Angeliq Hrt MJ. Reading and other learning difficulties. In: Rutter M, Taylor E, eds. Child and Adolescent Psychiatry, 4th Edition. Oxford, England: Blackwell Science; 2002:682-696 3. Berger M, Yule W, Rutter M. Attainment and adjustment in two geographical areas, II: the prevalence of specific reading retardation. Br J Psychiatry. 1975;126:510-519 4. Shaywitz SE, Shaywitz BA, Fletcher JM, Escobar MD. Prevalence of reading disability in boys and girls: results of the Connecticut