Leveraging Surprise: What Standards of Proof Imply that We Want from Jurors, and What We Should Say to Them to Get It

Abstract

This paper develops and defends the proposition that when humans evaluate evidence and determine what they believe in regard to facts, the primary, though usually implicit, operator in those determinations is, or at least ought to be, the fundamental emotion of surprise. It further asserts that this relationship between belief and surprise, at least in regard to anything with a defensible claim to the label “fact,” is one of entailment, or very nearly so. Finally, the paper shows that degrees of surprise can be relatively easily described and understood ordinally, and that asking questions about potential surprise is a much more fruitful way of determining and norming degrees of human belief in regard to facts, including those of jurors, than the hypothetical betting experiments favored by some, most notably, by neo-Bayesians seeking a way to derive cardinal numbers to incorporate into applications of Bayes’s rule.

Keywords: Evidence, standards of proof, probability, surprise

JEL Classification: COO, C11