New study finds 'delinquent behavior among boys contagious'

This release is available in French.

Montreal, July 16, 2009 – Impulsive boys with inadequate supervision, poor families and deviant friends are more likely to commit criminal acts that land them in juvenile court, according to a new study published in the Journal of Child Psychology and Psychiatry. The most surprising finding from the 20-year study, conducted by researchers from the Université de Montréal and University of Genoa, was how help provided by the juvenile justice system substantially increased the risk of the boys engaging in criminal activities during early adulthood.

"For boys who had been through the juvenile justice system, compared to boys with similar histories without judicial involvement, the odds of adult judicial interventions increased almost seven-fold," says study co-author Richard E. Tremblay, a professor of psychology, pediatrics and psychiatry at the Université de Montréal and a researcher at the Sainte-Justine University Hospital Research Center.

The research team sought out boys from kindergarten who were at risk for delinquent behavior and who were enrolled at 53 schools from the poorest neighbourhoods in Montreal. Some 779 participants were interviewed annually from the age of 10 until 17 years. By their mid-20s, some 17.6 percent of participants ended up with adult criminal records for infractions that included homicide (17.9 percent); arson (31.2 percent); prostitution (25.5 percent); drug possession (16.4 percent) and impaired driving (8.8 percent).

"The more intense the help given by the juvenile justice system, the greater was its negative impact," Dr. Tremblay stresses. "Our findings take on even greater importance given that the juvenile justice system in the province of Quebec has the reputation of being among the best. Most countries spend considerable financial resources to fund programs and institutions that group deviant youths together in order to help them. The problem is that delinquent behavior is contagious, especially among adolescents. Putting deviant adolescents together creates a culture of deviance, which increases the likelihood of continued criminal behavior."

"Two solutions exist for this problem," adds Dr Tremblay. "The first is to implement prevention programs before adolescence when problem children are more responsive. The second is to minimize the concentration of problem youths in juvenile justice programs, thereby reducing the risk of peer contagion."

The article, "Iatrogenic effect of juvenile justice," published in the Journal of Child Psychology and Psychiatry, was authored by Uberto Gatti of the University of Genoa, (Italy) and Richard E. Tremblay and Frank Vitaro of the Université de Montréal / Sainte-Justine University Hospital Research Center (Canada).

This study was funded by the Canadian Institutes of Health Research, the Fonds de la recherche en santé du Québec, the Fonds de recherche sur la société et la culture, the Social Sciences and Humanities Research Council.

About Journal of Child Psychology and Psychiatry: http://www3.interscience.wiley.com/cgi-bin/fulltext/122201997/PDFSTART
About the Université de Montréal: www.umontreal.ca/english/index.htm
About the Sainte-Justine University Hospital Research Center: www.recherche-sainte-justine.qc.ca/en/