Severity of autistic features is not easily defined and the use of different diagnostic tools compounds the ability to lay a clear cut definition. It is, though, generally accepted that children with autism and normal IQ (>70) are "high functioning" regardless of the severity of their autistic features. The investigators will use the terms "autism" and "ASD" interchangeably, and the term "low functioning autism" will be used to describe those children with autism who have, or are presumed to have, IQ<70.