Pro-environmental Self-Identity in Youth: Development and Validation of the ECO-SELF Questionnaire

Pro-environmental self-identity captures the extent to which one’s pro-environmental interests, values, and behaviors are central to how one sees oneself and one’s social groups. We introduce a new multi-dimensional measure of how youth form and maintain pro-environmental self-identity: the Exploration and Commitments for Sustainable Environmental Lifestyle Formation questionnaire (ECO-SELF). We assessed the psychometric properties of the ECO-SELF questionnaire in two samples of Dutch youth to develop (286 participants; Study 1) and confirm (1578 participants; Study 2) the structure and validity of the questionnaire. Additionally, Study 2 examined measurement invariance of ECO-SELF across gender and age groups. Findings showed that ECO-SELF is a multi-dimensional scale, capturing the dimensions Pro-environmental Exploration, Pro-environmental Centrality, and Pro-environmental Activism. We found meaningful associations between the ECO-SELF dimensions and measures of environmental self-identity, self-concept clarity, (climate-related) mental health, pro-environmental behavior, and collective climate intentions. These associations highlight the surplus value of our measure and stress the need for future research on pro-environmental self-identity processes to understand youth’s climate-related behavior and mental health. In Study 2, findings provided support for measurement invariance of the ECO-SELF questionnaire across gender and age groups. ECO-SELF provides researchers a convenient and comprehensive tool with strong preliminary psychometric properties to conduct research into youth’s pro-environmental self-identity development.