Recently developed models of fairness can explain a wide variety of seemingly contradictory facts. One of the most controversial and yet unresolved issues in the modeling of fairness preferences concerns the behavioral relevance of fairness intentions. Intuitively, fairness intentions seem to play an important role in economic relations, political struggles, and legal disputes but there is surprisingly little direct evidence for its behavioral importance. We provide experimental evidence for the behavioral relevance of fairness intentions in this paper. Our main result indicates that the attribution of fairness intentions is important in both the domains of negatively and positively reciprocal behavior. This means that equity models exclusively based on preferences over the distribution of material payoffs cannot capture reciprocal behavior. Models that take players' fairness intentions and distributional preferences into account are consistent with our data, while models that focus exclusively on intentions or on the distribution of material payoffs are not.