Another reason to love green space: It cuts teen violence

Teenagers living in neighbourhoods with more greenery may have less aggressive behaviours, suggests a new study.

Researchers at the University of Southern California (USC) recently conducted the first longitudinal study to see whether greenery surrounding the home could reduce aggressive behaviors in a group of Southern California adolescents living in urban communities.

The team followed 1,287 adolescents, age 9 to 18 years. They assessed the adolescents' aggressive behaviors every two to three years, asking parents if their child physically attacked or threatened others, destroyed things, or exhibited other similar behaviors. The researchers then linked the adolescents' residential locations to satellite data to measure the levels of greenery in their neighborhoods.

The study found that 9-18-year-olds who lived in places with more greenery had significantly less aggressive behaviors than those living in neighborhoods with less greenery. Both short-term (one to six months) and long-term (one to three years) exposure to greenspace within 1,000 meters surrounding residences were associated with reduced aggressive behaviors. The behavioral benefit of greenspace equated to approximately two to two-and-a-half years of adolescent maturation.

The study also found that factors such as age, gender, race/ethnicity, socioeconomic status, parents' educational background, occupation, income level, or marital status, and whether their mother smoked while pregnant or was depressed, did not affect the findings.

Additionally, these benefits existed for both boys and girls of all ages and races/ethnicities, and across populations with different socioeconomic backgrounds and living in communities with different neighborhood quality.

Researcher Diana Younan said that the study provides new evidence that increasing neighborhood greenery may be an effective alternative intervention strategy for an environmental public health approach that has not been considered yet.

Based on the study's findings, USC investigators estimate that increasing greenery levels commonly seen in urban environments could result in a 12 percent decrease in clinical cases of aggressive behavior in California adolescents living in urban areas.

This new knowledge may provide a strong reason for further studies to examine if improving greenery in residential neighborhoods will indeed reduce aggressive behaviors in adolescents.

The study will appear in the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP).