Male prevalence for reading disability is found in a large sample of Black and White children free from ascertainment bias
Male vulnerability to neurodevelopmental disorders remains controversial. For one disorder, reading disability, this sex bias has been interpreted as an artifact of referral bias. We investigated sex differences for the incidence of reading disability within a large prospective sample of White (N = 16,910) and Black (N = 15,313) children derived from the National Collaborative Perinatal Project (NCPP). Children were classified as having either moderate or severe reading disability when they had reading scores lower than 1.5 or 2.0 standard errors of prediction, respectively, given their age and intelligence. Reading disability was about twice as common in boys than girls (p < .001), irrespective of race, severity of disability, or exclusion of children with attentional disturbances or high activity levels. We conclude that there is a clear sex bias toward males for the incidence of reading disabilities. (JINS, 2000, 6, 433–442.)(Received June 29 1998)
(Revised April 21 1999)
(Accepted May 12 1999)
Key Words: Dyslexia; Sex differences; Sex ratio; Reading disability; Learning disability.
c1 Reprint requests to: Jacqueline Liederman, Brain, Behavior and Cognition Program, Boston University, 64 Cummington Street, Boston, MA 02215. E-mail: [email protected]