Can the outdoors heal us?

In the summer of 1869, John Muir would set out from his home bound for the Sierra Nevada and Yosemite—excursions he chronicled in his field journals (later shaped into My First Summer in the Sierra). It was reflecting on this kind of observational solitude—what Muir described as "constant communion with Nature"—that he later wrote a line we love:

“Everybody needs beauty as well as bread, places to play in and pray in, where Nature may heal and cheer and give strength to body and soul alike.”

His message is timeless. In a world too often plagued with violence, rancor, and short-sightedness, we are desperate for solutions. While most of what is discussed revolves around policy, institutions, and politics, an important healer is the one right outside the door. It starts with the simple act of taking your child outside.

Science Backs This Up

When Philadelphia ran a citywide cluster randomized trial to “green” vacant lots—plant grass and trees, clean trash, add simple fencing—low-income neighborhoods near treated lots saw about a 29% drop in gun violence, along with lower overall crime and fear.

An older study from 2001 based in Chicago found that buildings surrounded by more trees and grass had far fewer violent crimes than otherwise similar blocks, and residents living near greenery showed lower aggression (Kuo & Sullivan, 2001).

Newer studies echo this pattern: even passive exposure to nearby green space is linked to lower aggression—partly by boosting a person’s sense of control (Liu et al., 2024). Among youth, more neighborhood greenery has been tied to reductions in aggressive behavior roughly equal to two to two-and-a-half years of maturation (Younan et al., 2016).

This is not to say a park fixes everything, but it does mean that regular time outside—yards, sidewalks, schoolyards, trails—nudges behavior in the right direction. The outdoors has a real and positive impact on behavior and well-being.