De-Biasing Legal Fact-Finders With Bayesian Thinking.

This article shows how Bayesian thinking can help legal fact-finders to avoid some common fallacies and biases in the evaluation of legal evidence (false dichotomy, dependence neglect, and miss rate neglect).

Reasons Pro et Contra as a Debiasing Technique in Legal Contexts.

Although legal contexts are subject to biased reasoning and decision making, to identify and test debiasing techniques has largely remained an open task. We report on experimentally deploying the technique "giving reasons pro et contra" with professional ( N = 239) and lay judges ( N = 372) at Swedish municipal courts. Using a mock legal scenario, participants assessed the relevance of an eyewitness's previous conviction for his credibility. On average, both groups displayed low degrees of bias. We observed a small positive debiasing effect only for professional judges. Strong evidence was obtained for a relation between profession and relevance-assessment: Lay judges seemed to assign a greater importance to the prior conviction than professional judges did. We discuss challenges for future research, calling other research groups to contribute additional samples.

Prototype Effect and the Persuasiveness of Generalizations.

An argument that makes use of a generalization activates the prototype for the category used in the generalization. We conducted two experiments that investigated how the activation of the prototype affects the persuasiveness of the argument. The results of the experiments suggest that the features of the prototype overshadow and partly overwrite the actual facts of the case. The case is, to some extent, judged as if it had the features of the prototype instead of the features it actually has. This prototype effect increases the persuasiveness of the argument in situations where the audience finds the judgment more warranted for the prototype than for the actual case (positive prototype effect), but decreases persuasiveness in situations where the audience finds the judgment less warranted for the prototype than for the actual case (negative prototype effect).