ABSTRACT
Males are selectively afflicted with virtually every neurologic, psychiatric, and developmental disorder of childhood. There are conditions, of course, like anencephaly and dysraphism, which are commoner in females; but for the most important neurodevelopmental disorders-mental retardation, autism, hyperactivity, dyslexia, epilepsy, dysphasia, cerebral palsy, and conduct disorders-the sex differential works unequivocally to male disadvantage. This phenomenon is largely unexplained. Though the biology and psychology of sex differences has been an attractive area of recent scientific concern, the issue of selective male affliction seems to have generated neither broad interest nor systematic research. In its ubiquity and breadth, the phenomenon compels an explanation that is couched, somehow, in the biology of sex differences. According to C. Ounsted and D. C. Taylor, the increased variability expressed in males is at least in part a consequence of the function of the Y chromosome. In the neurodevelopmental disorders, sex differences cause a dissociation between the elements of frequency, or incidence, and intensity, or severity.
