Self‐interest is widely accepted as a powerful motivator by both academics and laypeople alike. However, research surrounding the self‐interest motive paints a complicated picture of this most important psychological construct. Additionally, research on the social desirability of self‐interest has revealed that despite its widespread acceptance, people do not readily accept that self‐interest drives their own behaviors. This paper reviews the literature on self‐interest and reveals several curious features surrounding its actual effect on helping behaviors, political attitudes and voting, and people's apparent ambivalence toward self‐interest as a motive. It is possible that norms against the expression of self‐interestedness evolved, creating ambivalence towards this widely accepted construct, subsequently affecting its expression on many human behaviors.