United neighbors take a bite out of crime

Scientists often explore the roots of violent crime by tracking individual qualities linked to such behavior. Kids, especially black males, who grow up in poor families headed by a single parent garner close scrutiny in this regard.

 A new investigation suggests that collective characteristics of certain neighborhoods help keep their crime rates down. Murders, physical assaults, and other violent acts occur less frequently in neighborhoods where residents know and trust one another, show a willingness to supervise children in public places, and take other steps to maintain social order, researchers report in the Aug. 15 Science.

 Neighborhoods that go begging for residents with a sense of unity and public duty incur the most numerous incidents of violent crime, regardless of the community's racial composition or average income, contends a research team headed by sociologist Robert J. Sampson of the University of Chicago. Sampson's group devised a measure of these neighborhood attributes, which they call collective efficacy.

"We're drawing attention to a collective influence on crime that makes common sense but is understudied and underappreciated," holds Felton Earls, a public health psychiatrist at Harvard University who participated in the new study. "If we can figure out how to strengthen collective efficacy, it may lead to substantial reductions in violent crime."

 The study drew on a 1995 survey of 8,782 adults, recruited at random from 343 Chicago neighborhoods. Neighborhoods were defined on the basis of census tracts, local conventions, and geographic landmarks. About 8,000 people inhabit each one.

 Many of the neighborhoods contain large majorities of white, black, or Latino residents. A small proportion features a mix of races and ethnic groups. Volunteers reported on community efforts to maintain social control by noting the extent to which their neighbors could be counted on to intervene if children skipped school and loitered on a street corner, if youngsters showed disrespect to an adult, if a fight broke out in front of their house, and if a local fire station faced budget cuts.

 Participants estimated community cohesion and trust by indicating the extent to which neighbors were close-knit, helped others, inspired trust, worked to get along with others, and shared the same values.

 From these responses, the researchers calculated levels of collective efficacy in each neighborhood.

 After controlling for race, age, measurement errors, and homicide rates in prior years, researchers found that collective efficacy rose sharply in neighborhoods with the lowest crime rates (obtained from 1995 police data on homicides and volunteers' reports of violent victimization in their neighborhoods). Collective efficacy influenced violent crime within neighborhoods more strongly than did widespread poverty, large numbers of first-generation immigrants, or transient occupancy of residences. Considerable residential transience does tend to erode collective efficacy, however, the researchers note.

 An unpublished analysis of the data also indicates that property crimes decline in neighborhoods identified as high in collective efficacy, Earls adds.

 The researchers plan to track collective efficacy and other factors, such as school truancy, thought to be related to violent crime in the same Chicago neighborhoods over the next 8 years. Discussions with residents will also delve into their ideas about how to stimulate collective efficacy, Earls says. Although neighborhood efforts aimed at encouraging trust and social control may make streets and homes safer, other social factors -- poverty, unemployment, lack of affordable housing -- exert crucial influences on violence in local communities, the Harvard scientist remarks.

 Investigators have long held that efforts at social control within neighborhoods influence violent crime rates, comments sociologist Richard B. Felson of the State University of New York at Albany. The new report takes an unusual position by analyzing social control as part of a collective trait rather than as a collection of individual behaviors, Felson asserts.

"We hope other researchers will now examine collective efficacy in the neighborhoods of different cities," Earls says.