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
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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