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.)