The purpose of the present study was to determine which behavioral and physical phenotypes would be most likely to divide the ASD population into discrete subgroups. The taxometric methods of Maximum Covariance (MAXCOV) and Minus Mean Below A Cut (MAMBAC) were employed to test for categorical versus continuous variation of each phenotype across…

Assessment of category knowledge and receptive language skills of 16 autistic (3-6 years old), mentally retarded, and normal children indicated that the autistic children's knowledge of function, form, and color categories was comparable to that of the mental-age-matched mentally retarded and normal comparison groups. (Author/DB)

A cluster analytic study was conducted to derive behaviorally homogeneous subtypes of pervasive developmental disorders (PDD) based on a range of behavioral symptoms that characterize autism. Analysis of data on 34 children with PDD, 27 of whom met criteria for autism, indicated 4 distinct groups differing on independent measures of social,…