Individuals' willingness to act in socially desirable ways, such as sharing resources with others and abiding by norms of ethical conduct, is a necessary condition of social life. The current research reconciles two seemingly contradicting sets of findings on the role of cognitive control in socially desirable behaviors. One set of findings suggests that people are tempted by self-serving impulses and have to rely on cognitive control overriding such impulses to act in socially desirable ways. Another set of findings suggests people are guided by other-regarding impulses and cognitive control is not necessary to motivate socially desirable behaviors. We provide a theoretical and empirical integration of these findings by identifying a key situational variable--the salience of interpersonal impact--that determines whether the dominant impulse is to behave in a self-serving or a socially desirable manner. We suggest that the dominant impulse is to behave in a socially desirable manner when the interpersonal impact of an action is salient, and that the dominant impulse is to behave in a self-serving manner when the interpersonal impact of an action is not salient. Consistent with this prediction, Studies 1-3 found that impairing participants' cognitive control led to less socially desirable behavior when interpersonal impact was not salient, but more socially desirable behavior when interpersonal impact was salient. Study 4 extended these findings by demonstrating that behaving in a socially desirable manner causes cognitive control impairment when interpersonal impact is not salient. But, when interpersonal impact is salient, behaving in a self-serving manner impairs cognitive control. We discuss the implications of our findings for understanding and managing socially desirable behaviors.