This study compared the performance of 17 children with autism, 17 children with mental retardation, and 31 normally developing children on a false belief task performance using a posting manipulation (a pictorial cue which facilitates the false belief performance of normal 3-year-olds). The performance of autistic children was significantly…

Evaluation of 17 children with autism at the ages of 6 to 15 and then again at ages 13 to 25, suggested that, for the majority of people with autism, there may be little development of a theory of mind. For a minority, development may extend to the equivalent of a 3- to 4-year-old level by the teenage years. (JDD)