Abstract
Background: Low socioeconomic status in childhood is a well-known predictor of subsequent criminal and substance misuse behaviors but the causal mechanisms are questioned.
Aims: To investigate if the associations between childhood family income and subsequent adolescent criminality and substance misuse are explained by unobserved familial risk factors.
Method: Swedish population-based quasi-experimental, family-based study following cohorts born 1989-1993 (ntotal=529,428; ncousins=262,816; nsiblings=217,035) from their 15th birthday up until the end of 2009.
Results: Children of parents in the lowest income quintile experienced a seven-fold increased hazard rate of being convicted of violent criminality compared to peers in the highest quintile (HR=6.84, 95% CI: 6.28-7.44). This association was entirely accounted for by unobserved familial risk factors (HR=0.99; 95% CI: 0.46-2.13). Similar pattern of effects was found for substance misuse.
Conclusions: There are no associations between childhood family income and subsequent violent criminality and substance misuse once unobserved familial risk factors are adjusted for.
