Changing environmental behaviour from the bottom up: The formation of pro-environmental social identities

Increasingly initiatives are formed from the bottom-up, by for example community members themselves, to stimulate pro-environmental behaviour in their overarching group. But can such bottom-up initiatives motivate pro-environmental behaviour, and why? I propose that perceiving a pro-environmental initiative as formed by regular group members themselves (i.e. from the bottom up) enables pro-environmental social identity formation, motivating behaviour accordingly. Three field studies around different initiatives supported this. Perceived bottom-up formation is positively associated with pro-environmental social identity (in content and strength), for members of the initiative (Study 1) and the overarching group (Study 2), and bottom-up pro-environmental initiative salience strengthens pro-environmental social identity in the overarching group (Study 3). Perceived bottom-up formation partly relates to self-reported pro-environmental behaviour (Study 2) and intentions (Studies 1 and 3) via pro-environmental social identity. Bottom-up pro-environmental initiatives may thus accelerate the transition towards pro-environmental practices; theoretical and practical implications are discussed.