Correlations for the Vineland Adaptive Behavior Scales with Kaufman Brief Intelligence Test in a forensic sample

People with an intellectual disability are over-represented in the criminal justice system in many western countries. Identifying accused persons with intellectual disability is important if they are to receive protections available under the law. Accurate diagnosis is also relevant for correctional administrators, probation and parole services, and community services. Diagnosis of intellectual disability must be made on the basis of both cognitive skills (intelligence) and adaptive behavior. In this study, the Kaufman Brief Intelligence Test assessed intelligence, and the Vineland Adaptive Behavior Scales assessed adaptive behavior, through self-report. Tests were administered to 150 offenders, ranging in age from 13 to 53 years, in Australian prisons, juvenile detention centers, legal aid offices, and probation services. Pearson product-moment correlation coefficients calculated among all subtests and between total scores were significant. ROC curve analyses demonstrated that performance on each effectively predicted a standard score of less than 70 on the other one.