The methodology of many studies that have identified specific genetic loci for disorders associated with mental retardation is criticized as failing to demonstrate an association between the behavior phenotype and the genetic marker. A more appropriate methodology using a multitrait-multimethod approach is suggested. (Author/JDD)

Assessment of 497 urban preschool children with developmental disabilities using the Vineland Adaptive Behavior Scales indicated a strong positive relationship between adaptive behavior and intelligence if measured globally. When Vineland domains were assessed separately, this relationship varied across domains and disability groups. With…