Littering is a global issue with serious environmental and economic impacts. But, what drives people to act responsibly? Sonny Rosenthal from Singapore Management University and Pengya Ai, a PhD student from Nanyang Technological University are interested in how social norms shape pro-environmental behaviour. Their research reveals how descriptive norms (what people do) and injunctive norms (what people should do) interact with personal responsibility, challenging assumptions about collective...