About 15 percent of school-aged children have a learning disability, and the findings suggest boys are at least twice as likely to have dyslexia, a learning disability that involves trouble with reading.
Reading difficulties can also be due to poor vision, hearing problems, emotional problems and attention-deficit/hyperactivity disorder (ADHD).
The research examined four previous large-scale studies of reading in children. The studies included 9,799 children 7 to 15 years of age, and in each study, around 50 percent of the children were boys.
A team of researchers found there are significant gender differences in reading. In each study boys were notably more likely to have dyslexia than girls. Across all the studies, about 20 percent of the boys had reading disabilities compared with about 11 percent of the girls.
The research implies that reading disabilities are genetic. Boys are more likely to have a range of developmental difficulties, and dyslexia is one of them.
The research also has wider implications for educationalists. The earlier learning difficulties are identified the better schools and parents will be at providing early treatment for those affected. The study suggests that educational programmes should address boys' early emerging disability.
The results are strong because the studies did not rely on children who were already known to be having learning difficulties - a weakness of some previous research.
Previous research has suggested the reason that reading disabilities are more common among boys is that teachers simply tend to recognise the problem in boys more often. It is sometimes thought that boys are more disruptive, so the teachers pay more attention to them. However, the new study found gender differences in a representative sample of children, suggesting that the numbers of those identified as having problems are accurate.
Dr Julia Carroll, a lecturer in psychology at the University of Warwick, said: "There has been an ongoing debate after some studies found that reading problems were equal for boys and girls, but this thorough large-scale study with should put that controversy to rest."
Dr Carroll, added: "Clearly, there is a higher percentage of reading-disabled males, which is consistent with most earlier studies. As reading disability in childhood is associated with adjustment problems in later life, there is a definite need to recognise sex differences."
For more information contact: Dr Julia Carroll, Psychology Department, University of Warwick, Tel: 44-247-652-3613, Email: J.M.Carroll@warwick.ac.uk or Jenny Murray, Communications Office, University of Warwick, Tel: 44-247-657-4255, Mobile: 07876217740
The study, that examined populations of students from New Zealand and the United Kingdom, is published in Journal of the American Medical Association, Vol 291, No16