Although Agnew's (1992) general strain theory (GST) has secured a fair degree of support since its introduction, researchers have had trouble explaining why some individuals are more likely than others to react to strain with delinquency. This study uses data from the National Survey of Children to address this issue. Drawing on Agnew (1997) and the psychological research on personality traits, it is predicted that juveniles high in negative emotionality and low in constraint will be more likely to react to strain with delinquency. Data support this prediction.

While immunosuppressive agents are used widely in the management of Crohn's disease, their efficacy has not been well established in randomised controlled trials. This study was designed to examine whether azathioprine increases remission rate when used in conjunction with a diminishing dose regimen of prednisolone over a period of 12 weeks. It further examined whether azathioprine offers any therapeutic advantage over placebo in the maintenance of remission in Crohn's disease over a period of 15 months. Sixty three patients with active Crohn's disease were treated with a 12 week diminishing dose of prednisolone and at the same time entered into a randomised, double blind 15 month trial of either azathioprine (2.5 mg/kg) or placebo. Remission rates between the two groups were compared at 12 weeks and at 15 months. There was no significant difference in the proportion of patients who had achieved and maintained remission by week 12 but at 15 months there was a highly significant difference in the proportion of patients in remission (42% receiving azathioprine v 7%/o receiving placebo), p=O0OO1. Using life tables this beneficial effect was reflected as the difference in the median number of days on the trial (p=0.02). There were significandy greater decreases over the trial period in the median erythrocyte sedimentation rate, C reactive protein, and leucocyte count in the azathioprine group. There were no cases of severe bone marrow suppression or clinical pancreatitis. In conclusion, azathioprine offers a therapeutic advantage over placebo in the maintenance of remission in Crohn's disease. (Gut 1995; 37: 674-678)

BackgroundChildhood lead exposure is a purported risk factor for antisocial behavior, but prior studies either relied on indirect measures of exposure or did not follow participants into adulthood to examine the relationship between lead exposure and criminal activity in young adults. The objective of this study was to determine if prenatal and childhood blood lead concentrations are associated with arrests for criminal offenses.Methods and FindingsPregnant women were recruited from four prenatal clinics in Cincinnati, Ohio if they resided in areas of the city with a high concentration of older, lead-contaminated housing. We studied 250 individuals, 19 to 24 y of age, out of 376 children who were recruited at birth between 1979 and 1984. Prenatal maternal blood lead concentrations were measured during the first or early second trimester of pregnancy. Childhood blood lead concentrations were measured on a quarterly and biannual basis through 6.5 y. Study participants were examined at an inner-city pediatric clinic and the Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio. Total arrests and arrests for offenses involving violence were collected from official Hamilton County, Ohio criminal justice records. Main outcomes were the covariate-adjusted rate ratios (RR) for total arrests and arrests for violent crimes associated with each 5 μg/dl (0.24 μmol/l) increase in blood lead concentration. Adjusted total arrest rates were greater for each 5 μg/dl (0.24 μmol/l) increase in blood lead concentration: RR = 1.40 (95% confidence interval [CI] 1.07–1.85) for prenatal blood lead, 1.07 (95% CI 0.88–1.29) for average childhood blood lead, and 1.27 (95% CI 1.03–1.57) for 6-year blood lead. Adjusted arrest rates for violent crimes were also greater for each 5 μg/dl increase in blood lead: RR = 1.34 (95% CI 0.88–2.03) for prenatal blood lead, 1.30 (95% CI 1.03–1.64) for average childhood blood lead, and 1.48 (95% CI 1.15–1.89) for 6-year blood lead.ConclusionsPrenatal and postnatal blood lead concentrations are associated with higher rates of total arrests and/or arrests for offenses involving violence. This is the first prospective study to demonstrate an association between developmental exposure to lead and adult criminal behavior.

Gottfredson and Hirschi's general theory of crime (1990) has generated an abundance of research testing the proposition that low self-control is the main cause of crime and analogous behaviors. Less empirical work, however, has examined the factors that give rise to low self-control. Gottfredson and Hirschi suggest that parents are the sole contributors for either fostering or thwarting low self-control in their children, explicitly discounting the possibility that genetics may play a key role. Yet genetic research has shown that ADHD and other deficits in the frontostriatal system are highly heritable. Our research thus tests whether "parents matter" in creating low self-control once genetic influences are taken into account. Using a sample of twin children we find that parenting measures have a weak and inconsistent effect. We address the conceptual and methodological issues associated with the failure to address genetic influences in parenting studies.More than a decade ago, Gottfredson and Hirschi (1990) set forth a general theory of crime that assigned low self-control as the causal factor in the etiology of crime and numerous analogous behaviors. Since that * We would like to thank the editor for his commitment to scholarly discourse.