Do children with PDDNOS have a theory of mind?

This study sought to differentiate PDDNOS from a similar nonautistic disorder (i.e., language impairment) on the basis of a cognitive deficit, theory-of-mind (ToM). ToM is an ability to infer mental states in others and has been found to be highly prevalent in autism, a disorder that shares many characteristics with PDDNOS (Baron-Cohen, 1985; Volkmar & Cohen, 1988). A sample of 28 children with either PDDNOS or a language impairment formed two groups (n = 14), matched on gender and verbal mental age. Participants were administered the brain function task (Baron-Cohen, 1989) and the false belief task (Perner, Frith, Leslie, & Leekam, 1989) to assess ToM. Results suggest that children with PDDNOS are deficient in a ToM ability, however, this relationship is not as strong as in previous studies with autistic samples, suggesting that children with PDDNOS may have a greater ToM ability. The existence of PDDNOS on the higher end of a spectrum of the Pervasive Developmental disorders as well as the construct of ToM itself existing on a continuum are discussed.