The study, conducted by Robert J. Sampson of Harvard University and Jeffrey D. Morenoff and Stephen Raudenbush of the University of Michigan, shows that the longstanding gap in the racial burden of violence follows a social anatomy and is not immutable.
The odds of committing violence are almost double for blacks as compared to whites and homicide is consistently ranked as the leading cause of death among young black men.
"The study shows that this disparity is largely social in nature and therefore amenable to intervention in community rather than individual settings," says Sampson, the Henry Ford II Professor of the Social Sciences in Harvard's Faculty of Arts and Sciences and lead author of the study, which was funded by the John D. and Catherine T. MacArthur Foundation, the National Institute of Justice and the National Institute of Mental Health.
Popular explanations of the racial gap in violence -- "constitutional" differences in IQ test scores and impulsivity or hyperactivity -- accounted for only 6 percent of the racial and ethnic disparities in violent behavior, the researchers found, while family poverty accounted for none of the gap.
In contrast, approximately 60 percent of the difference was explained by neighborhood environment, parents' marital status and immigrant status. Latinos are less likely than whites to engage in violent behavior, and contrary to popular stereotypes, first- and second-generation immigrants and neighborhoods that are immigrant enclaves exhibit lower than average violence.
For the study, which was designed to simultaneously assess competing hypotheses for racial and ethnic disparities in violence, the researchers sampled whites, blacks and Latinos from a diverse set of Chicago neighborhoods, ranging from highly segregated to very integrated. They analyzed violent offenses by almost 3,000 males and females ages 8 to 25, interviewing these individuals up to three times from 1995 to 2002. In addition, the study analyzed data from police records, the U.S. Census, and a separate survey of more than 8,000 Chicago residents who were asked about the characteristics of their neighborhoods.
The researchers found that residential segregation exposes black youth to neighborhoods with much higher levels of risk for violence and fewer protective factors than the neighborhoods where other racial and ethnic groups tend to live.
"Neighborhoods where more people have professional or managerial jobs are protective against violence," says Morenoff, a sociologist at the U-M Institute for Social Research. "So are neighborhoods with higher concentrations of immigrants. But in neighborhoods where residents express more cynicism towards the law and basic social norms about making money and taking responsibility for individual actions, young people are more likely to commit violent acts."
According to the authors, these results imply that interventions to integrate and improve neighborhood well-being, such as housing vouchers to promote class integration, may reduce the racial gap in violence.
Family social conditions matter as well, they note. While past attempts to address the racial gap in violence, including the 1965 Moynihan Report, tended to pathologize female-headed black families as a singular risk factor, the new study shows that whether a family is headed by a single parent or by two parents does not in itself predict violence. What does stand out is that youth whose parents are married are less likely to commit violence, suggesting the social benefits of marriage and labor-market policies that support stable marriages.
The study also attributes the low rate of violent behavior among Mexican-American youth to three protective factors: having married parents, living in neighborhoods with a high concentration of immigrants and their own first- or second-generation immigrant status.