Evidence from past pro-environmental programs suggests that the invalidation of individuals’ expectations could lead them to drop out of a given program. The aim of this research is to evaluate the impact of the invalidation of expectations on individuals’ commitment to a waste-sorting program. We focused on the hierarchy that may exist among these expectations by drawing on the dichotomy between central and peripheral cognitions proposed within the framework of the theory of social representations. In this perspective, expectations are the result of a body of socially constructed knowledge and can be characterized either by a central (essential) or peripheral (non-essential) status. Results show that withdrawing from the program is significantly more frequent when the experimenter invalidates a central cognition than when he invalidates a peripheral one. This moderating effect highlights the importance of taking into account representations with a view to explaining or preventing withdrawal from pro-environmental programs.