Emotion, belief, and the words of the law.

An assertion about a fact can in principle be tested in observations. That is impossible for assertions about what is permissible or obligatory, i.e., deontic assertions based on moral principles, conventions, rules, or laws. Many modal logics concern these matters. But an integrated theory of emotions and reasoning predicts that emotional reactions and strength of belief should be correlated for deontic assertions, but not for factual assertions. You can be convinced that it is wrong to take paperclips from the office, and that it is right for society to provide health care for everyone, and your emotional response to these two assertions is likely to correlate with the strength of your beliefs in them. In contrast, you can be convinced both that fresh snow is white and that fossil fuels are making the world hotter, but have an emotional reaction to only the second of these assertions. Grounds for factual assertions are empirical findings. But assessments of deontic assertions depend in part on the emotions that they elicit. Previous studies have corroborated this prediction for moral claims, matters of convention, prudential rules, and personal recommendations. We report two experiments that yield the same interaction for legal pronouncements from the Italian Civil Code compared with parallel factual assertions. People like propositions they believe, and they believe propositions they like. We discuss several remaining unknowns including the potential role of emotions in reasoning about legal and other deontic propositions.