| Within recent history, a number of significant advances in both philosophy and linguistics have been made by developing and applying frameworks for modality to topics such as causation (Lewis, 1973), conditionals (Bennet, 2003), knowledge (Nozick, 1981), and natural language modals (Kratzer, 2012). This dissertation proposes that the same basic approach can be fruitfully applied at the level of psychology. Specifically, it argues that progress on a number of different topics in psychology can be made through a systematic investigation of how people represent possibilities.;I begin by laying out a theoretical framework for the psychological representation of modality and demonstrates that it can unify an array of surprisingly diverse psychological phenomena. I then go on to provide direct empirical confirmation that the psychological representation of modality helps to explain the otherwise puzzling effects of morality on ordinary judgments of causation, freedom, doing/allowing, and intentional action. Finally, I test and confirm novel empirical predictions of the proposed account of the psychological representation of modality. The first is that young children's explicit judgments of possibility reflect morality's central place in the psychological representation of modality. The second is that this effect is not limited to children's explicit modal judgments but generalizes to non-linguistic judgments that involve modal representations. A more detailed overview of each chapter follows.;Chapter 1 outlines the linguistic framework for modality, focusing primarily on Kratzer's (1979; 1981; 2012) formalization, and proposes that a modified version of this basic framework may hold at a psychological level. It is then argued that providing a role for the psychological representation of modality would allow for a unified explanation of the impact of physical possibility, probability and morality on a diverse set of psychological phenomena including casual selection, judgments of force/freedom, counterfactual reasoning, the development of the understanding of possibility, and even modality in natural language. More specifically, it is suggested that each of these three factors (physical possibility, probability, morality) affects the psychological representation of modality and that the psychological representation of modality, in turn, plays a fundamental role in each of these different psychological phenomena.;Chapter 2 focuses on one of these three factors (morality) and presents an empirical confirmation of this basic proposal. Specifically, the results from these studies demonstrate that a measure of the relevance of alternative possibilities mediates the impact of morality on judgments of causation, freedom, doing/allowing, and intentional action. This approach provides a unified explanation for the impact of morality where one has previous been lacking. Additionally, this chapter provides empirical evidence that completely non-moral manipulations of the relevance of alternatives have the exact same impact on these four different kinds of judgments, confirming the more general role of the psychological representation of modality in these four different types of judgments.;Chapter 3 investigates the development of the psychological representation of modality in young children. Specifically, 3- to 7-year-old children and adults are asked to make judgments about whether an event is possible or impossible or whether the event would require magic to happen or not. Two studies demonstrate that children's judgments of possibility and magic are affected by physical, probabilistic and moral features of the events. In particular, younger (3- to 5-year-old) children tend to regard as impossible events which require violations of physics, are highly improbable, or involve immoral actions.;Chapter 4 tests whether this pattern of modal reasoning extends beyond children's linguistic responses by asking 4- to 9-year-old children to make non-linguistic predictions of others' future actions in a modified Dictator Game. Two studies provide evidence that younger (4- to 5-year-old) children's predictions are biased by their moral judgments in a way that is consistent with their explicit modal judgments of possibility. Specifically, they tend not to predict that other children their own age will behave selfishly, even though they themselves do, and also predict that others will behave less selfishly than they will in the future. |
