The literature about sustainable development emphasizes cooperation and participatory approaches as a major, if not a necessary, prerequisite for sustainable development. Therefore, if cooperation is necessary for sustainable development, it is not so much the assessment of the complexity of a value chain in itself which matters most, but the quality of the interactions between its stakeholders. Consequently, the quantitative and technical aspects of value chains should be analyzed through their contribution to the quality of the interactions between their stakeholders. Cognitive dissonance is one of the means to analyze the quality of interactions. We applied it to the domestic vegetable value chain in Martinique, a small island in the French West Indies. Cognitive dissonance is a state of mental conflict between values, beliefs, ideas or feelings. It is one of the major components for the success of cooperation in behavioral and cognitive sciences. The domestic vegetable value chain regroups about 2600 farmers. It can only supply 40% of the total demand. The gap is filled with imports. We analyzed the quantitative and qualitative dissonance patterns among 17 interacting stakeholders of the domestic vegetable value chain: farmers, wholesalers, collective catering, supermarkets managers, and agricultural institutions. We show that dissonance is the result of conflicting self-interests, conflicting business models, and conflicting public policies: individualistic behaviors vs collective action, market driven business models versus rent-seeking models, and European public policies not always adapted to small island economies. Recognizing and describing dissonance between the stakeholders of a value chain is a first step towards change in favor of sustainable and responsible value chains.