During the summer of 2019, I spent a couple of months working in Oakland, California, with Prevention Institute. Prevention Institute (PI) is a national nonprofit whose mission is to “build prevention and health equity into key policies and actions at the federal, state, local, and organizational level to ensure that the places where all people live, work, play and learn foster health, safety and wellbeing” (Prevention Institute, n.d.). PI is organized into a number of key focus areas, including “mental health and wellbeing,” “quality housing in equitable communities,” “healthy food and activity environments,” and “preventing violence.” Different teams of PI employees are devoted to individual focus areas.

During my internship, I worked primarily with the “preventing violence” team. I organized data for various ongoing projects, compiled information about organizations that PI has partnered with or interviewed, and conducted a literature review of greening (building green space into city and residential landscapes). For this literature review, I focused on the potential of greening to reduce rates of violence and related, ongoing greening initiatives. The following is a condensed version of the piece I wrote in collaboration with Christine Williams of PI.

Greening as a Violence Prevention Strategy

An ever-growing number of studies link green space with mental health and wellbeing. And this connection is intuitive. People have long retreated to parks and natural places to recharge from the pressures of daily life. Less widely recognized is the potential of greening as an effective violence prevention strategy.

Greening vacant lots, revitalizing parks and recreational areas, and creating new green spaces has multiple benefits. Communities that implement greening can improve mental and physical health outcomes; reduce stress, aggression, and the incidence and severity of psychiatric conditions; increase social interaction; enhance childhood development; and minimize stormwater runoff (Kuo et. al, 2001). And, greening can reduce and prevent violence, especially when it’s part of a comprehensive prevention strategy that involves community developers, public health practitioners, and residents (Prevention Institute, 2019).

the proof is in the greening

In 2018, researchers in Philadelphia partnered with the community to convert vacant lots into small parks as part of a violence prevention strategy. The city contains over 44,000 vacant lots, many located in low-income areas. Researchers randomly assigned over 500 of these lots to three groups. The first group of lots were cleaned and “greened” with vegetation, the second set were just cleaned, and the third were left untreated. The neighborhoods surrounding the lots in the two groups that received treatment exhibited significant decreases in crime and violence. Results were especially impressive in areas where residents’ incomes were below the poverty line (Branas et. al, 2018).

A Chicago study that involved 145 women living in public housing found that exposure to green surroundings reduces mental fatigue and improves the ability to concentrate and willingness to handle problems more deliberately and less aggressively. Of the women interviewed in this study, those living near trees and green spaces reported less aggression and violence than did those living in park-poor areas. Chicago is now following the Philadelphia model, recruiting people who’ve experienced and perpetrated violence to revitalize vacant lots (Kuo et. al, 2001).

The same Chicago study found that even adding just a few trees helped residents feel safer. Similar findings were revealed in a 2012 study done in Portland, Oregon—the presence of trees in public streets correlated with decreased violence (Donovan & Presteman, 2012).