New research finds yet another benefit to living in close contact with the natural environment.

By Tom Jacobs

(Photo: ellenm1/Flickr)

It’s the call no parent wants to get: one from a school official, or, worse, a police officer, informing them their kid has gotten into yet another fight. This sort of belligerent behavior can be triggered in teenagers by everything from violent video games to divorce, but new research points to another, more subtle factor: whether they are growing up surrounded by trees and grass.

In a first-of-its-kind longitudinal study, researchers from the University of Southern California report urban adolescents who grow up in neighborhoods with more greenery are less likely to engage in aggressive behavior.

Importantly, this association “could not be explained by sociodemographic factors or neighborhood quality,” writes a research team led by Diana Younan and Jiu-Chiuan Chen. What’s more, it applied to both boys and girls, and teens of all races and ethnicities.

Perhaps what cities with youth-crime epidemics really need are not more police, but more parks.

Many studies have found nature is soothing to adults, and a few have linked kids’ exposure to green space to enhanced cognitive abilities. But this is the first to specifically explore the relationship between abundant vegetation and adolescent aggression.

The study followed 1,287 youngsters from 640 families in greater Los Angeles. Each was assessed at least twice between the ages of nine and 18 for aggressive behavior. Parents filled out the widely used Child Behavior Checklist, in which they report whether their child gets into fights, destroys things, or threatens others. They rate such behaviors on a scale from “never” to “very true” or “often true.”

The green space around the youngsters’ homes was determined via satellite imagery. Researchers calculated the amount of vegetation up to 1,000 meters from their residence (about six-tenths of a mile).

“We found strong evidence supporting the benefits of neighborhood green space in reducing aggressive behaviors,” the researchers write. “The results of our adjusted analyses suggest a consistent pattern of decreased aggression associated with increasing residential green space within a 1000-meter buffer.”

They found no evidence this impact was limited to wealthier or poorer neighborhoods, and report it still held true after accounting for such factors as traffic density and proximity to freeways.

The researchers describe several “possible pathways” that could explain their results. Easy access to the natural world may reduce maternal stress, which can lead to children acting out. It can encourage physical activity, reduce air pollution levels, and “act as a buffer for ambient noise.”

In addition, they write, green space in urban areas has been shown to preserve “the microbial biodiversity needed to drive immunoregulation, and to optimize brain health.”

Whatever the specific mechanisms, there are clear mental-health benefits to engaging with the natural environment, and this research strongly suggests that equation applies to teens as well as adults.

Perhaps what cities with youth-crime epidemics really need are not more police, but more parks.

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