A Three-Dimensional Behavior Model of Environmentally Responsible Sustainability Bridging Psychology, Ethics, and Environment

The continuous growth of the tourism industry has made the issue of tourists’ environmentally responsible behavior (ERBR) an urgent issue in both academic and policy terms. This research aims to develop a conceptual model through the integration of the Theory of Planned Behavior (TPB), the Norm Activation Model (NAM), and environmental factors to analyze the mechanisms that influence tourists’ intentions and behaviors to be environmentally responsible. Data were collected from 400 Thai tourists and analyzed using the Partial Least Squares Structural Equation Modeling (PLS-SEM) technique. The results indicate that the research model can comprehensively explain tourists’ behaviors. Internal mechanisms such as attitudes, subjective norms, perceived behavioral control, and personal norms all have significant influences on environmentally responsible behavioral intention and environmentally responsible behaviors. In particular, the norm internalization process shows that subjective norms can be systematically transformed into internal ethical values, which is key to fostering long-term sustainable behavior. This model provides a comprehensive theoretical understanding of environmentally responsible tourism behavior and can be used to effectively design policies and proactive activities to promote environmentally responsible tourist behaviors in the long term.