Making Pledges More Powerful: Effects On Pro-Environmental Beliefs And Conservation Behavior

We developed pledges that capitalized on several self-related properties (e.g., freedom of choice, actual-ought self-discrepancies, foot-in-door technique) and manipulated two experimental factors: pledge beneficiary and pledge audience. In two studies, participants received a recycling pledge based on a random assignment in a 2 (Beneficiaries: Nature vs. Self) x 2 (Audience: Ingroup vs. Outgroup) design. Afterwards, we assessed their pro-environmental beliefs and provided them with a behavioral opportunity to support conservation (i.e., recycling debriefing forms in Study 1, writing letters to congresspeople regarding an environmental policy in Study 2). In both studies, an interaction between beneficiaries and audience was observed, showing that a recycling pledge framed as benefitting nature and sponsored by a social ingroup led to more progressive environmental beliefs. In Study 2, individuals in the same condition (i.e., the nature-ingroup pledge) wrote more persuasive letters (longer and more sophisticated letters) supporting pro-environmental legislation. Implications for constructing effective pledges and for leveraging the self to promote pro-environmental action are discussed.