Explanations for Apparent Late Onset Criminality in a High-Risk Sample of Children Followed up in Adult Life

Abstract

We examined the psychiatric and forensic histories of 13 individuals whose first officially recorded criminal conviction took place after their 22nd birthday, and compared the levels of disturbance among that group with those from the same high-risk sample who had (a) no recorded convictions, (b) convictions only up to age 21, and (c) convictions before and after age 22. Among the 13 with recorded convictions only after age 22, there was evidence of at least minor juvenile delinquency in every case but one, and of major adult mental illness whose onset preceded first conviction in four cases. Levels of childhood antisocial behaviours were significantly higher among that group than among those who had never been convicted, and levels of major mental illness were significantly higher than among those who had never been convicted and those with convictions only up to age 21. Apparent late onset criminality in the present sample was therefore associated with known risk factors for adult criminality, in the form of juvenile antisocial behaviour and/or major mental illness. Officially recorded criminality consistently shows a small but significant number of individuals whose criminal activity appears to begin relatively late in life, that is after adolescence. In one large follow-up of unselected schoolchildren in Sweden, for example, 25 per cent of the males with a criminal record had their first conviction aged 21 or older. Among the females, 52 per cent of those with a criminal record had their first conviction at 21 or older (Stattin et al. 1989). The number of males with registered criminality only after age 21 (64 out of 709) was smaller by comparison with other groups of offenders than would be predicted from a random model (Stattin and Magnusson 1996), but still represented 9 per cent of the total male sample. In another unselected birth cohort of over 6,000 females born in Stockholm, Sweden in 1953, criminal records data revealed that 237 individuals had their first criminal registration after age 18. At 3.5 per cent of the total sample this was the largest group of offenders, compared with those who began offending before age 15 and persisted throughout life, those who offended only during adolescence, and those who offended in a less persistent way before and after age 18 (Kratzer and Hodgins 1996). Similar proportions with apparent late onset criminality have been found among groups who would be expected to be at higher risk for criminality, like clinic samples and those enrolled in social interventions. In McCord’s (1978) follow-up of 506 boys in the Cambridge-Somerville Youth Study, 41 of the 317 boys (13 per cent) with no official juvenile record of delinquency were convicted of serious crimes as adults, with few