I'll scratch your back if you give me a compliment: Exploring psychological mechanisms underlying compliments'...

Although compliments can be an effective compliance tactic, little is known about the reasons for their effectiveness. Two studies tested three potential mechanisms underlying the use of compliments as a compliance tactic: reciprocity, positive mood, and liking. In both studies, participants were either primed with the reciprocity norm or not, then received either complimentary or neutral feedback from a stranger. Participants were later faced with a request from the stranger. Mood, liking for the requestor, and compliance were measured. As predicted, compliments increased compliance in both studies. Neither study found evidence for positive mood nor liking as a mediator of the compliment effect. However, reciprocity priming was found to moderate the compliment effect in both studies, suggesting that compliments are effective, at least in part, because they invoke the reciprocity norm.