Background: Younger siblings of children with autism spectrum disorders (ASD) are at higher risk for acquiring these disorders than the general population. Language development is usually delayed in children with ASD. The present study examines the development of pre-speech vocal behavior in infants at risk for ASD due to the presence of an older…

Objective: To examine the implications for research of the use of three alternative definitions for Asperger syndrome (AS). Differences across the three nosologic systems were examined in terms of diagnostic assignment, IQ profiles, comorbid symptoms, and familial aggregation of social and other psychiatric symptoms. Method: Standard data on…

This paper examines the validity of Asperger syndrome as a condition apart from high-functioning autism. Potential differences between Asperger syndrome and autism is possible if both are strictly defined. The importance of genetic factors in Asperger syndrome is stressed. Research on the nosological validity of this condition and its relationship…