Parental separation at birth and criminal behaviour in adulthood

Abstract.

Background: Parental absence has been connected with later criminality. We studied the association between very early separation and criminality in a unique data set. Methods: The index cohort consisted of 2,906 subjects born between 1945 and 1965 in Finland who were temporarily isolated from their family immediately after birth and sent to adequate nursing homes due to tuberculosis in the family. The average separation time was 7 months. For every index subject, two reference subjects (matched for sex, year of birth and place of birth) were gathered. Data on criminal offences were obtained from Statistics Finland arising from adolescence to middle age, between January 1, 1977 and December 31, 1998. The association between parental separation and subcategories of non-violent and violent criminality and violent recidivism, respectively, in male and female offspring was analysed. Subjects who had committed at least two violent crimes were defined as violent recidivists. Results: Of the male index subjects, 12.1% as compared with 7.1% of the reference cohort (estimated relative risk RR 1.73; 95% CI 1.42–2.11) had committed violent offences. Of the male index subjects 5.2% and of the male reference subjects 3.6% were violent recidivists (RR 1.47; 1.10–1.98). Of the male index subjects 26.3% and of the reference cohort 23.4% had committed nonviolent crimes (RR 1.14; 1.01–1.29). Among females, non-violent crimes were committed by 7.9% of the index subjects and by 5.0% of the reference subjects, respectively (RR 1.54; 1.18–2.00). Violent crimes were rare among female subjects. Conclusion: Criminal behaviour was more prevalent among both male and female subjects separated at birth from their families because of tuberculosis in the family than in the reference cohort. Especially violent crimes were prevalent in the male index cohort. Even so, the differences between the index and reference cohorts were rather modest. Very early separation may have some, although limited, influence on later criminality in the offspring.