Violence can rise with the heat, experts say

By David Steinkraus

Tuesday, July 19, 2005 2:03 AM CDT

RACINE - No one yet has apportioned blame for Sunday morning's triple homicide, but aside from gangs or guns, we could look at the weather.

"Generally speaking, we can say that temperature does affect crime," said Dennis Rosenbaum of the University of Illinois-Chicago. Rosenbaum, 53, is a professor of criminal justice and director of the university's Center for Research in Law and

Justice.

That applies to violent crime, he said, and people who have done studies over a period of 40 years have found that annual temperatures predict rates of assaults and robberies. Higher temperatures mean more violent crimes; lower temperatures mean fewer violent crimes - to a point. Once temperatures get too hot for people to be outside, violent crimes will decrease.

"However, domestic violence does not follow that pattern," said Will Pelfrey, 34, assistant professor of criminal justice at the University of Wisconsin-Milwaukee. "Domestic violence does continue to increase as the temperature increases."

That's because domestic violence happens at home, and when it's too hot people don't leave the house, so other crimes decrease, Pelfrey said.

The temperature threshold above which those other violent crimes decrease is about 94 degrees, he said, although this varies depending on the temperatures that people are used to. So it's higher in the South but a few degrees lower here.

Of course, homicides also occur in December, Rosenbaum said, so one needs to distinguish assaults, typically committed by strangers, from homicides, in which the killers often know their victims.

There are two competing theories about how crime happens, Rosenbaum said.

The "routine activity theory" says that crime happens when motivated offenders and potential victims come together in the absence of guardians, such as the police or witnesses. "If it's too hot people may not be out as much (to prevent crime), and if it's too cold they're not out," he said.

The general aggression theory says that when the temperature rises people don't feel comfortable, Rosenbaum said. They're more frustrated, more hostile, and, thus, are more aggressive.

Crime increases proportionately with the temperature in affluent communities, too, Pelfrey said, although people there also have a way to mitigate frustration: air conditioning. Many prisons in the Southwest are air conditioned, he said, and while citizens complain about the cost, removing the air conditioning and cable television means the prisoners would fight more, creating a danger to the prison staff as well as themselves. "And medical expenses vastly outweigh the savings of removing cable television and air conditioning from corrections facilities."

Particularities Generalities are one thing, but in reality one needs to look at crime circumstances, Rosenbaum said. Racine's shootings, while they occurred during a hot spell, may have been the result of a simmering gang feud, he said. (Racine police haven't announced that gangs are involved, although gang unit officers are helping in the investigation.) Insults build, Pelfrey said, and with guns in their pockets, people don't resort to fistfights to settle arguments.

"That's what we're seeing in Milwaukee, and that's what's happening in Racine," he said.

Temperatures in Racine over the weekend reached into the high 80s.

"The weather didn't help," Rosenbaum said. "It was probably just another mediating factor that played some role in pushing them over the edge."

Gang problems make it incumbent on the city to have a long-term plan, Rosenbaum said, because related to that violence is the number of children and teens who are not employed, not enrolled in after-school programs, and not doing well in school.

"Unlike bigger cities, you (Racine residents) have the capacity, I think, to keep this under control," he said. "I'm not saying you'll get rid of it because gangs are a part of the social fabric of our society where we have various social classes."

The warming Cooler weather may bring relief from crime, but the weather overall isn't getting cooler. Craig Anderson, a professor and chairman of the psychology department at Iowa State University in Ames, Iowa, has said recent improvements in the violent crime rate in America may be lost as global warming continues.

With colleague Brad Bushman, a psychology professor at the University of Michigan, Anderson predicted a violent trend in the U.S. crime rate as temperatures increase with global warming. Every 1-degree increase in the average temperature will increase the U.S. murder and assault rate by about 4 people for every 100,000, they wrote. The finding was published in 1998 by the American Psychological Association, and was part of an article analyzing 10 years of studies by social psychologists.

"With a population of 270 million people, that translates into roughly 9,900 more murders and assaults per year if global warming increases the average temperature by only 1 degree Fahrenheit," they wrote.

Even this estimate may be overly optimistic, they wrote.

"If global warming progresses as now seems likely, we can expect the recent reductions in the U.S. violent crime rate to disappear, only to be replaced by a steadily climbing rate of violence, along with all the grief, anguish, costs and waste associated with it," they wrote.

Tom Barton contributed to this report.

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