How expert witnesses' counterfactuals influence causal and responsibility attributions of mock jurors and expert judges

Past research has shown that counterfactual (“If…then…”) thoughts influence causal and responsibility attribution in the judicial context. However, little is known on whether and how the use of counterfactuals in communication affects lay jurors' and judges' evaluations. In two studies, we asked mock lay jurors (Study 1) and actual judges (Study 2) to read a medical malpractice case followed by an expert witness report, which included counterfactuals focused on either the physician, the patient, or external factors. Results showed that counterfactual focus had a strong effect on both lay jurors' and judges' causal and responsibility attributions. Counterfactual focus also moderated the effect of outcome foreseeability on responsibility attribution. Discussion focuses on how counterfactual communication can direct causal and responsibility attribution and reduce the importance of other factors known to influence judicial decision-making. The potential implications of these findings in training programs and debiasing interventions are also discussed.