When judging their likelihood of success in competitive tasks, people tend to be overoptimistic for easy tasks and overpessimistic for hard tasks (the shared circumstance effect; SCE). Previous research has shown that feedback and experience from repeated-play competitions has a limited impact on SCEs. However, in this paper, we suggest that competitive situations, in which the shared difficulty or easiness of the task is more transparent, will be more amenable to debiasing via repeated play. Pairs of participants competed in, made predictions about, and received feedback on, multiple rounds of a throwing task involving both easy- and hard-to-aim objects. Participants initially showed robust SCEs, but they also showed a significant reduction in bias after only one round of feedback. These and other results support a more positive view (than suggested from past research) on the potential for SCEs to be debiased through outcome feedback.

Above-and-below-average effects are well-known phenomena that arise whencomparing oneself to others. Kruger (1999) found that people rate themselves asabove average for easy abilities and below average for difficult abilities. Weconducted a successful pre-registered replication of Kruger’s (1999)Study 1, the first demonstration of the core phenomenon (N =756, US MTurk workers). Extending the replication to also include abetween-subject design, we added two conditions manipulating easy and difficultinterpretations of the original ability domains, and with an additionaldependent variable measuring perceived difficulty. We observed anabove-average-effect in the easy extension and below-average-effect in thedifficult extension, compared to the neutral replication condition. Bothextension conditions were perceived as less ambiguous than the original neutralcondition. Overall, we conclude strong empirical support for Kruger’sabove-and-below-average effects, with boundary conditions laid out in theextensions expanding both generalizability and robustness of the phenomenon.

Rational trust decisions depend on potential outcomes and expectations of reciprocity. In the trust game, outcomes and expectations correspond to the structural factors of risk and temptation. Two experiments investigated how risk and temptation influenced information search and final decisions in the trust game. The central finding was that trustors underemphasized temptation relative to its effects on the expected value of trust. Instead, trustors made decisions egocentrically, focusing on potential outcomes. In Experiment 1, information search data revealed that trustors often made decisions without learning about the payoffs related to temptation. Experiment 2 investigated whether trustors were able to use temptation to form accurate expectations of reciprocity. Trustors understood, but underestimated, the relationship between temptation and the probability of reciprocity. Moreover, they did not fully consider expectations in their final trust decisions. Changes in potential outcomes had larger effects on trust than comparable changes in expectations. These results suggest that levels of trust are too high when the probability of reciprocity is low and too low when that probability is high.