Feeling duped is an aversive emotional response to the perception of having been taken advantage of in a interpersonal transaction (primarily those involving economic exchange), partly as a result of one's own decisions. The actual likelihood of being duped, as well as the heightened vigilance for it, should increase as a function of opportunity (e.g., information asymmetry that gives one side a big advantage in knowledge) and motivation (e.g., an exceptionally huge payoff may make it worth defrauding a long-term business partner). Being duped produces an aversive self-conscious emotion with a threat of self-blame. There appears to be stable individual differences in the motivation (called sugrophobia) to avoid being a sucker. High sugrophobes will be vigilant and skeptical of potential deals. Low sugrophobes may not even realize in some instances that they were duped. The aversive reaction to feeling duped stimulates counterfactual ruminations that may intensify sugrophobia but also aids in extracting useful lessons.