AbstractPeople’s evaluations of events often depend on their expectations about those events. There is often disappointment when events fail to meet expectations—sometimes even when the events are still positive overall—and there is a special thrill to having one’s expectations exceeded. In this dissertation I propose a theory of event evaluation based on contrasts between global representations of states of the world that accounts for the role of expectations in evaluations. I then present four studies showing evidence for this model in moral and non-moral domains. In Study 1, I generated quantitative predictions from the model to fit existing data describing people’s emotional reactions to risky monetary gambles. Study 2 is a naturalistic study examining football fans’ reactions after wins and losses based on their Twitter activity. Fans’ reactions are influenced by their prior expectations of winning or losing each game. The evaluation of events is intimately linked to the evaluation of actions, in that one mode for evaluating action is simply to evaluate the events brought about by those actions. Consequently, Studies 3 and 4 shift focus to judgments of moral actions. In Study 3, participants were asked to contrast pairs of identical actions taken against victims in different circumstances. Participants’ expectations about victims’ prior risk affected their moral judgments of the actions so that a victim’s greater prior risk mitigated the severity of their moral judgments. Study 4 examined a naturalistic dataset of global Twitter activity in response to terrorism events. Terrorism events evoked larger public reactions when those events were surprising, with weaker reactions resulting when terrorism occurred in countries that suffer from high rates of terrorism. Finally, I discuss the implications of these findings for the normative status of human moral judgments. I discuss how expectations may play a role in the omission-commission distinction, moral luck, and victim blaming. Although it seems justifiable that expectations influence evaluations of non-moral events, in judgments of moral actions this tendency may lead to pervasive moral error.