Following Europe’s lead, American schools are considering giving students more recess time, and now researchers from the University of Illinois are looking into the benefits of teaching class outdoors too.

According to “attention restoration theory,” natural landscapes soothe and calm our “mental muscle.” After it’s had a moment to rest, our capacity to direct attention is refreshed.

Kuo’s earlier research has shown natural, green environments reduce aggression and ADHD symptoms while promoting academic achievement.