Mentally retarded offenders: Prevalence and characteristics

The range of prevalence rates for retarded offenders reported in the literature varies from 2.6 to 39.6 percent. This wide variability appears to be due to the use of different population bases and to the way intelligence is measured. When these issues were explored empirically, prevalence rates for retarded offenders in two northeastern states were found to be only slightly higher than the prevalence rate of mental retardation in the general population. A second issue in the literature is identification of the predictors of offenders' offense severity, sentence length, and past recidivism. Results of this study showed that social and legal variables are better predictors than is intelligence, although no predictors were particularly strong.