Autism spectrum disorders (ASD) include everything from the relatively mild Asperger syndrome (characterized by more mild social and language impairments) to full-fledged autism (characterized by severe social and communicative handicaps, limited interests, and repetitive behaviors). ASD is relatively common, and in the United States it is estimated that one out of every 54 boys is affected (the frequency in girls is considerably lower, averaging one affected girl out of every 252). Although...