Five studies explored whether power undermines the quality of relationships by creating instrumental attributions for generous acts. We predicted that this cynical view of others' intentions would impede responses that nurture healthy relationships. In the first three studies, the powerful were more likely to believe that the favors they received were offered for the favor-giver's instrumental purposes, thereby reducing power-holders' thankfulness, desire to reciprocate, and trust. These effects emerged when power was manipulated through hierarchical roles or primed semantically, and when participants recalled past favors or imagined future ones. Using income disparity as a proxy for power, Study 4 found that instrumental attributions for favors in marriages led to lower levels of reported relationship commitment among high-power spouses. Study 5 provided evidence that favors are critical in triggering power-holders' diminished trust. We connect our theory and findings to both a political scientist's writings on the nature of love and power almost half a century ago as well as the dilemma voiced by many celebrities who find true relatedness elusive. Overall, power provides a reason to doubt the purity of others' favors, creating a cynical perspective on others' generosity that undermines relationships.