The Criminality of Noninstitutionalized Mentally Retarded Persons

Abstract

This study examines the criminality of noninstitutionalized mentally retarded (NIMR) men and women in a Swedish birth cohort composed of 15,117 participants followed from before birth to age 30. NIMR participants were compared with participants who had never been placed in a special class or in an institution for the mentally retarded or admitted to a psychiatric ward (NMR). NIMR participants were more likely than NMR participants to have been convicted for a criminal offense before age 30 and for a violent offense. NIMR offenders had been convicted, on average, for the same number of offenses as NMR offenders. Among the NIMR offenders, 71% of men and only 43% were first convicted before the age of 18. For both NIMR men and women, childhood conduct problems were found to be associated with adult criminality.