The psychology of moral versus factual reasoning.

Abstract

The theoretical framework for this research contrasting moral and factual reasoning was derived from moral philosophy, research in the Kohlbergian tradition, social psychological research on attitude change, and research in judgment and decision making on biases in reasoning. Based on this work, moral reasoning is characterized as rule-based (top-down) and hence less sensitive to amount of evidence (number of arguments) favoring a given position, compared to factual reasoning which was expected to depend on amount of evidence. Argument processing in moral reasoning was also predicted to be more subject to confirmatory bias. 480 students read arguments, some of which confirmed, while others disconfirmed, their prior opinions. The arguments were either moral or factual in nature, the number of arguments was either high or low, and the target issue was varied (capital punishment versus teaching values in the public schools). Overall opinion, moral opinion, factual opinion, and convincingness of each argument were rated. Moral and factual reasoning were both subject to bias (overweighting of confirmatory arguments), although the former slightly more so. Also as predicted, amount of evidence had a significant effect for factual reasoning, but not for moral reasoning. Arguments exerted cross-category effects on opinion change (e.g. moral arguments on factual opinions), although within-category effects were larger. Path analysis indicated, however, that moral and factual arguments did not exert direct effects on cross-category judgments. In other words, moral arguments did not directly effect factual conclusions, nor vice versa, but were instead mediated through overall opinion. Finally, convincingness ratings exhibited a kind of compensatory equilibrium such that when the majority of arguments was disconfirmatory, the few confirmatory arguments were rated as more convincing in both moral and factual reasoning. Thus, this study indicates that moral and factual reasoning are similar in that they are both subject to opinion bias, but they differ in the kinds of judgments they directly influence, and in their responsiveness to amount of evidence. Therefore these data support a characterization of moral reasoning as rule-based and factual reasoning as evidence-based.